Elasto-plastic analysis and strength checking method, device and equipment under multiple working conditions and medium

Abstract

This invention relates to the field of structural design and strength assessment technology for nuclear fusion devices, and discloses a method, apparatus, equipment, and medium for elastoplastic analysis and strength verification under multiple operating conditions. First, the basic parameters, element partitions, and condition constraints of the target structure are obtained. Next, static nonlinear solutions are performed based on the basic parameters, element partitions, and condition constraints to obtain the target dataset and load-displacement curves. Different stress stages are abstracted as continuous gravity loading paths. A single elastoplastic analysis process is used to simultaneously evaluate the strength and deformation under multiple operating conditions, moving beyond the limitations of linear elastic calculations under a single condition and more realistically reflecting the actual stress state of the structure. Subsequently, based on the load-displacement curves, the allowable gravity amplification factor is determined. Further, based on the allowable gravity amplification factor, the target dataset, and the load-displacement curves, the safe strength elastoplastic results and high-risk areas are determined. Finally, based on the high-risk areas and preset reinforcement rules, a reinforcement scheme is obtained.

Description

Technical Field

[0001] This invention relates to the field of structural design and strength assessment technology for nuclear fusion devices, and in particular to a method, apparatus, equipment and medium for elastoplastic analysis and strength verification under multiple operating conditions. Background Technology

[0002] As a promising nuclear fusion reactor structure, the tokamak device typically has a cold shield structure installed on the outside of its vacuum chamber.

[0003] In related technologies, the design and verification of cold-screen structures are mainly based on linear elastic finite element analysis, using the material's yield strength as the criterion. This method can only evaluate the safety during the elastic stage and cannot describe the changes in the structure's load-bearing capacity after it reaches yield. Therefore, a new method for elastoplastic analysis and strength verification under multiple working conditions is needed. Summary of the Invention

[0004] The embodiments described in this specification aim to at least partially solve one of the technical problems in the related art. To this end, the embodiments described in this specification propose a method, apparatus, equipment, and medium for elastoplastic analysis and strength verification under multiple working conditions.

[0005] This specification provides a method for elastoplastic analysis and strength verification under multiple working conditions, the method comprising:

[0006] Obtain the basic parameters, element partitions, and condition constraints of the target structure;

[0007] Based on the aforementioned basic parameters, the aforementioned element partitioning, and the aforementioned conditional constraints, static nonlinear solutions are performed to obtain the target dataset and load-displacement curves.

[0008] Based on the load-displacement curve, determine the allowable gravity amplification factor;

[0009] Based on the allowable gravity amplification factor, the target dataset, and the load-displacement curve, the safety strength elastoplastic results and high-risk areas are determined.

[0010] Based on the high-risk areas and the preset reinforcement rules, a reinforcement scheme is obtained.

[0011] In one implementation, the static nonlinear solution based on the basic parameters, the element partitioning, and the conditional constraints to obtain the target dataset and load-displacement curves includes:

[0012] Based on the gravity amplification factor corresponding to the current working condition and the unit partition, the equivalent inertial force is determined;

[0013] Based on the equivalent inertial force, an elastic analysis is performed to determine the elastic response results;

[0014] When the elastic response result indicates an unsafe condition, a static nonlinear solution is performed based on the basic parameters, the element partitioning, and the conditional constraints to obtain the target dataset and load-displacement curves.

[0015] In one implementation, the basic parameters include thickness data of each component, and the acquisition of unit partitions includes:

[0016] The target structure is divided into partitions based on its actual function, stress characteristics, and geometry to obtain the basic structure partitions.

[0017] Based on the thickness data and geometric features of each component, the basic structure partition is divided into unit types to obtain the unit partition.

[0018] In one implementation, the basic parameters include the true stress-true strain curve for each material, and obtaining each of the true stress-true strain curves includes:

[0019] Obtain the engineering stress-engineering strain curves for each material in the target structure;

[0020] Based on the engineering stress-engineering strain curve corresponding to each material, the true stress-true strain curve corresponding to each material is obtained by conversion.

[0021] In one implementation, the static nonlinear solution based on the basic parameters, the element partitioning, and the conditional constraints to obtain the target dataset and load-displacement curves includes:

[0022] Based on the aforementioned basic parameters, unit partitioning, and conditional constraints, a static nonlinear solution is performed to obtain the overall maximum displacement of the target structure, the maximum equivalent stress of the material location structure, and the maximum equivalent plastic strain of the key area corresponding to each load step.

[0023] The load-displacement curve is obtained by pairing the target structure's overall maximum displacement corresponding to each load step.

[0024] In one implementation, determining the allowable gravity amplification factor based on the load-displacement curve includes:

[0025] Based on the load-displacement curve, determine the slope of the curve in the elastic stage;

[0026] Based on the slope of the elastic stage curve, the reduction factor, and the load-displacement curve, the plastic limit gravity amplification factor is determined.

[0027] The permissible gravity amplification factor is determined based on the plastic limit gravity amplification factor and the safety reduction factor.

[0028] In one implementation, the safety strength elastoplastic result includes a safety result and a strength elastoplastic result. Determining the safety strength elastoplastic result based on the allowable gravity amplification factor, the target dataset, and the load-displacement curve includes:

[0029] The safety result is obtained based on the allowable gravity amplification factor and the gravity amplification factor under actual working conditions;

[0030] Based on the gravity amplification factor under actual working conditions and the target structure's overall maximum displacement, material position structure's maximum equivalent stress, and key area's maximum equivalent plastic strain corresponding to each load step, the target structure's overall maximum displacement, material position structure's maximum equivalent stress, and key area's maximum equivalent plastic strain under actual working conditions are determined.

[0031] Based on the target structure's overall maximum displacement, the material position structure's maximum equivalent stress, and the key area's maximum equivalent plastic strain under the actual working conditions, the strength-elastic-plastic results are obtained.

[0032] In one implementation, high-risk areas are identified based on the target dataset, including:

[0033] Based on the gravity amplification factor under actual working conditions and the maximum equivalent plastic strain in the key area corresponding to each load step, the maximum equivalent plastic strain in the key area under actual working conditions is determined.

[0034] Based on the maximum equivalent plastic strain in the key area under the actual working conditions and the corresponding local plastic strain risk threshold, high-risk areas are determined.

[0035] In one embodiment, the method further includes:

[0036] Based on the target dataset, data is aggregated to obtain operating condition curves and envelopes;

[0037] Based on the operating condition curve and the envelope, results are obtained for scheme selection and safety assessment.

[0038] In one embodiment, the method further includes:

[0039] Measure the maximum displacement and gravity amplification factor of the target structure under actual working conditions;

[0040] The parameters to be calibrated are combined to obtain a vector of constituent parameters.

[0041] An error function is constructed based on the maximum displacement, the gravity amplification factor, and the parameter vector;

[0042] Based on the error function, the target parameter vector is determined, and elastic-plastic analysis and strength verification under multiple working conditions are performed based on the target parameter vector.

[0043] In one embodiment, the method further includes:

[0044] Based on the target structure, determine the design variables to be calibrated;

[0045] Based on the design variables to be calibrated, constraints, and objective function, the target design variables are determined, and the target structure is updated based on the target design variables.

[0046] This specification provides a device for elastoplastic analysis and strength verification under multiple working conditions, the device comprising:

[0047] The target structure data acquisition module is used to acquire the basic parameters, cell partitions, and condition constraints of the target structure.

[0048] The static nonlinear solution module is used to perform static nonlinear solutions based on the basic parameters, the element partitioning, and the condition constraints to obtain the target dataset and load-displacement curves.

[0049] The permissible gravity amplification factor determination module is used to determine the permissible gravity amplification factor based on the load-displacement curve.

[0050] The analysis results and risk area determination module is used to determine the safety strength elastoplastic results and high-risk areas based on the allowable gravity amplification factor, the target dataset, and the load-displacement curve;

[0051] The reinforcement scheme generation module is used to obtain a reinforcement scheme based on the high-risk area and preset reinforcement rules.

[0052] This specification provides a computer device comprising: a memory, and one or more processors communicatively connected to the memory; the memory stores instructions executable by the one or more processors, the instructions being executed by the one or more processors to cause the one or more processors to perform the steps of the method described in any of the above embodiments.

[0053] This specification provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in any of the above embodiments.

[0054] This specification provides a computer program product that includes instructions that, when executed by a processor of a computer device, enable the computer device to perform the steps of the method described in any of the above embodiments.

[0055] In the above-described implementation method, firstly, the basic parameters, element partitions, and condition constraints of the target structure are obtained. While controlling the computational scale, the ability to distinguish stress and plastic strain in local details is maintained, thereby significantly improving the accuracy of identifying local hazardous areas. Next, a hybrid element elastoplastic model that considers both overall and local accuracy is constructed. Static nonlinear solutions are performed based on the basic parameters, element partitions, and condition constraints to obtain the target dataset and load-displacement curves. Different stress stages are uniformly abstracted into a continuous gravity loading path. A single elastoplastic analysis process is used to simultaneously evaluate the strength and deformation under multiple working conditions, moving beyond linear elastic verification under a single working condition and more realistically reflecting the actual stress state of the structure throughout its entire lifespan. Subsequently, based on the load-displacement curves, the allowable gravity amplification factor is determined, clarifying the maximum size of the working conditions the structure can withstand and the remaining safety margin from the ultimate limit state under the current working condition, thereby enhancing the reliability of design and on-site decision-making. Furthermore, based on the allowable gravity amplification factor, the target dataset, and the load-displacement curve, the safe strength elastoplastic results and high-risk areas are determined, enabling refined management of local yielding. This avoids the overly conservative approach of immediately deeming the structure unqualified upon yielding, while ensuring the overall structural safety. Finally, based on the high-risk areas and pre-defined reinforcement rules, reinforcement schemes are derived, avoiding modifications to the structure based on experience and improving the targetedness and efficiency of reinforcement design. Attached Figure Description

[0056] Figure 1 A flowchart of the multi-condition elastoplastic analysis and strength verification method provided for the embodiments of this specification;

[0057] Figure 2 A flowchart illustrating the preconditions for elastoplasticity verification provided in the embodiments of this specification;

[0058] Figure 3 A schematic diagram of the process for obtaining unit partitions provided for the implementation of this specification;

[0059] Figure 4 A schematic diagram of the process for obtaining the true stress-strain curve for each material, provided for the implementation of this specification.

[0060] Figure 5 A schematic flowchart illustrating the process of obtaining load-displacement curves for embodiments of this specification;

[0061] Figure 6 A flowchart illustrating the determination of the permissible gravitational amplification factor provided for the implementation of this specification;

[0062] Figure 7 A flowchart illustrating the determination of the safety strength elastoplastic result for the embodiments described in this specification;

[0063] Figure 8 A flowchart illustrating the process of determining high-risk areas provided for the implementation of this specification;

[0064] Figure 9 A flowchart illustrating the process of obtaining results for scheme selection and safety assessment provided for the implementation of this specification;

[0065] Figure 10 A flowchart illustrating the process of performing elastoplastic analysis and strength verification under multiple working conditions based on the target parameter vector, as provided in the embodiments of this specification.

[0066] Figure 11 A flowchart illustrating the process of determining target design variables and updating the target structure based on the target design variables, provided for the implementation of this specification.

[0067] Figure 12 A flowchart illustrating the multi-condition elastoplastic analysis and strength verification method provided in the embodiments of this specification;

[0068] Figure 13 A schematic diagram of the multi-condition elastoplastic analysis and strength verification device provided for the embodiments of this specification;

[0069] Figure 14 An internal structural diagram of a computer device provided for embodiments of this specification. Detailed Implementation

[0070] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0071] As the most promising nuclear fusion reactor structure for engineering applications, tokamak devices typically have a cold shield structure installed on the outside of the vacuum chamber. The cold shield, serving as a low-temperature thermal radiation shielding and support insulation component, primarily blocks the transfer of heat radiation between the vacuum chamber and the superconducting magnet, maintaining the magnet's low-temperature operating environment. It also bears a certain structural load-bearing function. During device pre-assembly, docking, and lifting, the cold shield must temporarily withstand its own weight and external support reaction forces.

[0072] The cold screen of a tokamak has the following structural characteristics:

[0073] (1) It is composed of irregularly shaped components such as thin-walled panels, lugs, and reinforcing ribs. There are many geometric discontinuities, which can easily lead to stress concentration.

[0074] (2) The cold screen is large in size and has a high degree of thinness. Under multi-directional gravity and off-center load conditions, it is prone to large overall deformation and local yielding.

[0075] (3) The connection between the cold shield and the upper vacuum chamber assembly relies on temporary supports. The load path is complex during the hoisting stage, and the safety margin is not easy to judge directly.

[0076] (4) Welded joints, stiffener weld toes and other areas are high-risk areas, and residual stress and manufacturing errors will further weaken the structural bearing capacity.

[0077] In related technologies, the design and verification of cold screen structures mainly employ two types of methods:

[0078] 1. Based on linear elastic finite element analysis, using the material yield strength as the criterion, it can only evaluate the safety in the elastic stage and cannot describe the change in the load-bearing capacity of the structure after it enters the yield stage.

[0079] 2. Based on the empirical safety factor method, the verification is directly performed by increasing the margin according to the self-weight condition, which makes it difficult to quantify the impact of local yielding on the overall structural safety.

[0080] However, during assembly and transportation, cold-faced surfaces may face transient hypergravity conditions and high local constraints, often resulting in limited plastic deformation in practice. Single linear elasticity or simple safety factor verification methods have the following limitations:

[0081] 1. The overall plastic limit load-bearing capacity of the cold screen cannot be accurately assessed.

[0082] 2. It is impossible to determine whether local yielding is within a controllable range.

[0083] 3. There is a lack of unified and quantitative evaluation indicators for safety margins under various operating conditions.

[0084] 4. It is difficult to provide a basis for the reinforcement design of high-risk areas such as lifting lugs.

[0085] In related technologies, the strength analysis of the vacuum chamber, thermal / cold shield, and related supporting structures in tokamak devices mostly employs the finite element method to assess the stress and deformation of the structure under typical working conditions such as gravity, thermal load, earthquake, and electromagnetic fields. The results are then verified using linear elastic analysis combined with allowable stresses or safety factors specified in the standards. For example:

[0086] In the design and analysis of the thermal shield structure of the EAST device, finite element software such as NASTRAN and ANSYS were used to conduct stress analysis on the thermal shield under various load combinations such as gravity, earthquake, electromagnetic force and thermal gradient, and this was used as the basis for structural optimization design and verification. However, the research mainly stayed at the level of elastic strength verification and did not systematically examine the load-bearing capacity and plastic development of the structure after it entered yield.

[0087] In the thermo-mechanical coupling analysis of the vacuum chamber heat shield structure of the DTT device, a finite element model including the vacuum chamber and the vacuum chamber heat shield (VVTHS) was established. Shell elements, beam elements and coupling equations were used to simulate the heat shield plate, cooling pipes and bolt connections. The displacement and stress distribution under periodic temperature cycles and thermal loads were evaluated, and structural optimization suggestions were proposed. However, the work mainly focused on the thermo-mechanical response and the influence of temperature-related material properties on stress distribution, and did not involve the load-bearing capacity assessment under hypergravity conditions, temporary hoisting supports and local plastic buckling.

[0088] In the thermal-structural analysis of the vacuum chamber and cryogenic shield / cold shield system of the SST-1 device, ANSYS was used to analyze the stress and deformation of the vacuum chamber and cryogenic shell under loading scenarios such as vacuuming and thermal conditions. The safety of the structure under various loading conditions was discussed, providing a basis for structural design. However, the models are mostly based on the assumption of linear elastic materials and relatively simplified structural details, and lack specific characterization of the plastic behavior and post-yield safety margin of local high-stress areas such as lifting lugs, stiffeners, and weld transition zones.

[0089] In the design of thermal and cryogenic shielding structures for devices such as ITER, finite element comparative analyses of thermal shield panels, supporting components, and their hoisting and assembly fixtures were conducted to verify the structural integrity and safety of related hoisting adapters for thermal or cold shields (such as the hoisting adapter for the lower cryogenic shielding layer). Although attention has begun to be paid to hoisting conditions, linear elastic models are mostly used, mainly focusing on stress peaks and displacement control for single or a few conditions. A comprehensive system for evaluating and verifying the elastoplastic bearing capacity across multiple conditions has not yet been established.

[0090] In summary, the relevant technologies still have significant shortcomings in the following aspects:

[0091] (1) The analysis is limited to the linear elastic range: elastic stress and displacement are the main criteria for judgment. There is a lack of systematic quantification of the bearing capacity of cold screen after yielding under hypergravity, eccentric loading and complex constraints. It cannot answer the key engineering question of "whether the structure is still safe after a certain plastic deformation".

[0092] (2) Model simplification leads to insufficient description of local behavior: In order to take into account the scale of calculation, complex geometric and connection details such as lifting lugs, stiffeners, and weld transition zones are usually simplified, making it difficult to accurately capture local stress concentration, plastic strain distribution and yield zone range, which is not conducive to proposing targeted reinforcement and optimization schemes.

[0093] (3) Lack of a zoned verification approach of “overall safety + controllable local yield”: The stress or displacement control criteria are often uniformly adopted globally, and local yield is often regarded as not allowed, or simply compared with the maximum stress and yield strength. This may be too conservative and cannot distinguish between “acceptable local plasticity” and “unacceptable failure risk”. There is a lack of engineering criteria for the controllability of local yield.

[0094] (4) Lack of a unified load-bearing capacity envelope and safety margin assessment mechanism for multiple working conditions: For multiple actual working conditions such as assembly, lifting, transportation, operation and extreme accidents, they are often carried out separately. There is a lack of a unified assessment method to extract the relationship between "load-displacement-plastic development" through elastoplastic analysis, and thus form a plastic ultimate bearing capacity and allowable working condition range of cold screen structure. It is difficult to provide a quantitative decision basis for lifting scheme comparison, temporary support arrangement and structural reinforcement.

[0095] In summary, the design and analysis of tokamak cold screen structures can be categorized into the following six specific issues:

[0096] (1) Accuracy issues in modeling and analyzing complex structures of cold screens:

[0097] The cold shield of a tokamak consists of various components such as thin-walled panels, lugs, stiffeners, supports, and welded transition zones. It has strong local geometric discontinuities. The traditional oversimplification modeling method, which is used to reduce the computational scale, cannot simultaneously take into account the overall stiffness response and the accuracy of stress and strain distribution in local high-stress areas. This makes it impossible to accurately determine the plastic development and yield range of key risk areas such as lug holes and support weld toes.

[0098] (2) Problems with insufficient unified characterization of multiple working conditions and load path description:

[0099] The load forms and constraints experienced by cold-faced panels vary significantly at different stages, including pre-assembly, temporary support, hoisting, transportation, and operation, including self-weight, hypergravity acceleration, eccentric support reaction force, and assembly deviations. Existing methods typically perform linear elastic analysis for each working condition separately, lacking an analytical path that can uniformly map multiple working conditions into a "load-deformation-yield evolution" relationship, and thus failing to form a comparable and quantifiable safety margin evaluation system between working conditions.

[0100] (3) The problem of difficulty in quantifying the plastic ultimate bearing capacity and the allowable working condition range:

[0101] When a cold screen enters the elastoplastic stage under certain working conditions, the traditional method of judgment based on a simple comparison of maximum stress and yield strength cannot answer key engineering questions such as "whether the structure still has sufficient load-bearing capacity under finite plastic deformation" and "what is the corresponding maximum allowable acceleration or load". It is also difficult to deduce the safe working condition window and plastic ultimate bearing capacity based on the analysis results.

[0102] (4) The problem of lack of zonal verification criteria for overall safety and controllable local yielding:

[0103] While the overall structure of a cold-faced shield can maintain elasticity or slight plasticity under most working conditions, stress concentration or even yielding inevitably occurs in areas of abrupt geometric changes (such as lifting lugs, supports, and weld transition zones). Existing methods have not yet established a zonal strength determination criterion of "controlled overall stiffness and displacement + controllable local plastic strain," and cannot distinguish between acceptable local yielding and unacceptable failure risks, nor can they guide engineering projects to adopt local reinforcement rather than overly conservative overall design.

[0104] (5) The lack of a systematic process for high-risk area identification and simulation-driven hardening design:

[0105] During the design and verification of cold-stripped surfaces, engineers need to quickly identify and quantify high-plastic-strain areas to determine whether optimization of lifting lugs, stiffener placement, plate thickness, or weld transition is necessary. However, existing analysis results are mostly presented in the form of cloud maps, which are highly subjective, lack unified thresholds and quantitative evaluation indicators, and make it difficult to form a standardized closed-loop process of "high-risk area identification - reinforcement scheme recommendation - design iteration".

[0106] (6) Problems with insufficient feasibility of the project and inadequate alignment with standards:

[0107] While existing research has made some progress in theoretical analysis and numerical simulation, it has not yet systematically integrated the results of elastoplastic finite element analysis with the load-bearing capacity assessment methods in engineering specifications (such as evaluation rules based on plastic limit theory). There is a lack of an operational method that can be directly used for engineering design approval, scheme comparison and selection and on-site safety assessment, which makes it difficult to directly transform simulation results into engineering decision-making basis.

[0108] Based on the above analysis, the relevant technologies are still in the design verification stage, which is mainly based on linear elasticity verification. A system strength verification and load-bearing capacity assessment method that is oriented towards cold-faced structures, covers multiple working conditions, and considers the evolution of elastic-plastic behavior has not yet been established. It is difficult to accurately assess the true load-bearing capacity of cold-faced structures after local yielding or even limited plastic deformation. There is a lack of a unified process for identifying local yielding areas and simulation-driven reinforcement design. It is impossible to provide reliable simulation basis and quantitative criteria for cold-faced structure design optimization, local reinforcement, and hoisting scheme formulation.

[0109] Based on the above analysis, this specification provides a method for elastoplastic analysis and strength verification under multiple working conditions. First, the basic parameters, element partitions, and condition constraints of the target structure are obtained. While controlling the computational scale, the ability to distinguish stress and plastic strain in local details is maintained, thereby significantly improving the accuracy of identifying local hazardous areas. Next, a hybrid element elastoplastic model that considers both overall and local accuracy is constructed. Static nonlinear solutions are performed based on the basic parameters, element partitions, and condition constraints to obtain the target dataset and load-displacement curves. Different stress stages are uniformly abstracted into a continuous gravity loading path. A single elastoplastic analysis process is used to simultaneously evaluate the strength and deformation under multiple working conditions, moving beyond linear elastic verification under a single working condition and more realistically reflecting the actual stress state of the structure throughout its entire lifespan. Subsequently, based on the load-displacement curves, the allowable gravity amplification factor is determined, clarifying the maximum size of the working conditions the structure can withstand and the remaining safety margin from the ultimate limit state under the current working condition, thereby enhancing the reliability of design and on-site decision-making. Furthermore, based on the allowable gravity amplification factor, the target dataset, and the load-displacement curve, the safe strength elastoplastic results and high-risk areas are determined, enabling refined management of local yielding. This avoids the overly conservative approach of immediately deeming the structure unqualified upon yielding, while ensuring the overall structural safety. Finally, based on the high-risk areas and pre-defined reinforcement rules, reinforcement schemes are derived, avoiding modifications to the structure based on experience and improving the targetedness and efficiency of reinforcement design.

[0110] This specification provides a method for elastoplastic analysis and strength verification under multiple working conditions. Please refer to [link / reference]. Figure 1 The method for elastoplastic analysis and strength verification under multiple working conditions may include the following steps:

[0111] S110. Obtain the basic parameters, element partitions, and condition constraints of the target structure.

[0112] Specifically, for the target structure, it is first necessary to comprehensively obtain its 3D model, 2D design drawings, and complete technical data (usually including design specifications, material properties, load standards, etc.). Then, based on the technical data and 2D design drawings, fundamental parameters such as geometric dimensions, material mechanical properties, and connection methods are extracted. Combining the actual state and usage requirements of the target structure, boundary conditions, load cases, displacement constraints, and other constraints are defined to provide a basis for subsequent analysis. Based on the 3D model, the structure is meshed using appropriate element types (such as solid elements, shell elements, or beam elements), and the structure is divided into several element partitions according to geometric characteristics or analysis requirements to support subsequent numerical calculations and analysis. The target structure can be a tokamak cold screen.

[0113] For example, basic parameters may include material grade, density, elastic modulus, Poisson's ratio, and yield strength. At least one material grade (such as austenitic stainless steel, carbon steel, etc.) is determined for the tokamak cold shield. Then, based on the material grade, the corresponding density, elastic modulus, Poisson's ratio, yield strength, and engineering stress-strain curve are determined from the technical data corresponding to the tokamak cold shield. For instance, if the material grade A of the cold shield panel is determined, the corresponding density is determined based on material grade A. Elastic modulus Poisson's ratio Yield stress 1. Engineering stress-strain curve. Determine the material grade B of the lifting lug / support, and determine the corresponding density based on material grade B. Elastic modulus Poisson's ratio Yield stress 2. Engineering stress-strain curve. Determine the material grade C of the stiffener, and determine the corresponding density based on the material grade C. Elastic modulus Poisson's ratio Yield stress 3. Engineering stress-engineering strain curve.

[0114] For example, although the two-dimensional design drawings contain some basic parameters (such as the dimensions, arrangement, and connection relationships of components), the simulation software cannot automatically recognize the text and annotation information in the drawings. Therefore, it is necessary to extract data from the two-dimensional drawings and input the extracted parameters into the software. The parameters that need to be extracted and input mainly include the following:

[0115] 1. Geometric dimensions of the cold screen panel, such as panel thickness, arc length, and width.

[0116] 2. Dimensional parameters of the lifting lugs, such as plate thickness, support thickness, and hole diameter.

[0117] 3. The cross-sectional parameters of the reinforcing ribs or steel sections, such as width, height, and spacing.

[0118] 4. The connection positions and forms between the cold shield and the vacuum chamber, supporting structure, and temporary supports.

[0119] 5. Parameters such as weld type, weld length, and transition fillet radius.

[0120] For example, the setting of condition constraints may include the following:

[0121] 1. Simulation of the superstructure or supporting device:

[0122] Cold shields are typically suspended by steel structures such as beams, hangers, hooks, and lugs, or connected to the vacuum chamber, support frame, etc. In the finite element model, appropriate constraints need to be applied at these connections to simulate the actual support effect.

[0123] If the on-site connection is a rigid hanging beam, a method close to "fixed constraint" can be used in the simulation.

[0124] If suspended by means of flexible connection, pulley, etc., "spring constraint" can be used, or only constrain part of the direction.

[0125] For example, displacement constraints in three directions can be applied to the inner nodes of the lug to simulate a rigid suspension; or a system with specified stiffness can be introduced. The spring unit simulates a semi-rigid connection.

[0126] and / or

[0127] 2. Simulation of temporary supports and lifting slings:

[0128] In practical engineering, cold shields may be supported by temporary supports or suspended by hoisting slings. To reflect the actual stress and support states under different working conditions, equivalent simulations can be performed in the model using constraints, contact, or spring elements.

[0129] Constraints: Set the displacement of a specific node or surface in a specified direction to zero to simulate a support state that is "held up" or "locked". For example, when a cold screen rests on a rigid pad, the contact point can be constrained in the vertical direction; if suspended by a rigid lug, the displacement of the inner ring nodes of the lug can be constrained in all three directions.

[0130] Contact: Used to simulate the interaction between two components, where "force is transmitted during compression and freedom is allowed during separation," and to transmit pressure during contact. Contact corresponds to support conditions that allow both force transmission during compression and separation. For example, when a cold shield is placed on a temporary support, surface-to-surface contact can be used to realistically reflect the state of force transmission during compression and separation during lifting.

[0131] Spring elements: Used to simulate elastic, non-rigid connections that allow for minute displacements. Spring elements correspond to support conditions of "elastic connection, allowing for minor deformation." For example, when lifting slings have a certain amount of elongation, or when the support structure exhibits elastic deformation, spring elements can be set between the cold-screen node and the virtual support point, and their stiffness values ​​can be specified.

[0132] S120. Static nonlinear solution is performed based on basic parameters, element partitioning, and condition constraints to obtain the target dataset and load-displacement curves.

[0133] S130. Based on the load-displacement curve, determine the allowable gravity amplification factor.

[0134] S140. Based on the allowable gravity amplification factor, target dataset, and load-displacement curve, determine the safety strength elastoplastic results and high-risk areas.

[0135] Specifically, after determining the basic parameters, element partitions, and condition constraints, these need to be used as input data for static nonlinear solutions. Based on these inputs, the static nonlinear solution of the structure is performed by gradually applying loads or displacement controls. This process simulates the entire process of the structure from elasticity and yielding to collapse, ultimately outputting the target dataset and load-displacement curves. According to the load-displacement curves, combined with preset reduction factors, the allowable gravity amplification factor of the target structure can be determined, reflecting the amplification capacity of the load that the structure can withstand relative to the design load when reaching the specified performance state. Finally, by combining the allowable gravity amplification factor, detailed target datasets, and complete load-displacement curves, the safety strength elastoplastic results of the structure under expected stress can be systematically evaluated. By analyzing the stress-strain concentration, high-risk areas in the structure can be accurately identified, thus providing a key basis for structural performance evaluation and reinforcement design. If the safety strength elastoplastic results indicate that both the overall and local safety strength and elastoplastic results meet the requirements, it can be determined that the strength and stiffness of the target structure under the corresponding working condition meet the expected standards.

[0136] S150. Based on high-risk areas and preset reinforcement rules, a reinforcement plan is obtained.

[0137] Specifically, the system has a pre-built set of reinforcement rules based on the regional structural type and mechanical properties. For identified high-risk areas, the system will automatically match and generate corresponding reinforcement schemes based on their specific location, stress mode, and damage mechanism.

[0138] In some implementations, the preset reinforcement rules may include the following aspects:

[0139] Panel area: Prioritize thickening the panel, adding local reinforcing ribs, and shortening the unsupported span.

[0140] Lifting lugs and support area: Prioritize increasing plate thickness, increasing corner radius, adding transition plates, and optimizing lug shape.

[0141] Reinforcing rib area: Adjust the height and width of the ribs, change the spacing of the ribs, add or move the ribs.

[0142] Weld seams and geometric transition zones: Increase transition fillet radius, lengthen transition section, optimize weld toe transition shape, etc.

[0143] For example, specific reinforcement solutions may include:

[0144] 1. Increase the thickness of local plates or increase the cross-sectional dimensions of key components such as lifting lugs and supports. For example, increase the thickness of local plates. Adjusted to .

[0145] 2. Optimize the arrangement and quantity of reinforcing ribs. For example, increase the spacing between reinforcing ribs from... Adjusted to , or cross section made of Adjusted to

[0146] 3. Improve the weld transition shape, such as by using a larger fillet radius and reducing geometric abrupt changes. For example, reduce the fillet radius of the weld transition from... Adjusted to .

[0147] It should be noted that after adjusting the target structure according to the reinforcement scheme, elastoplastic analysis and strength verification under multiple working conditions should be carried out again. This process needs to be repeated until the overall performance and local details of the structure meet the design requirements, thus forming a simulation-guided design optimization closed loop.

[0148] In the above implementation, firstly, the basic parameters, element partitions, and condition constraints of the target structure are obtained. While controlling the computational scale, the ability to distinguish stress and plastic strain in local details is maintained, thereby significantly improving the accuracy of identifying local danger zones. Next, a hybrid element elastoplastic model that considers both overall and local accuracy is constructed. Static nonlinear solutions are performed based on the basic parameters, element partitions, and condition constraints to obtain the target dataset and load-displacement curves. Different stress stages are uniformly abstracted into a continuous gravity loading path. A single elastoplastic analysis process is used to simultaneously evaluate the strength and deformation under multiple working conditions, moving beyond linear elastic calculations for a single working condition and more realistically reflecting the actual stress state of the structure throughout its entire lifespan. Subsequently, based on the load-displacement curves, the allowable gravity amplification factor is determined, clarifying the maximum size of the working conditions the structure can withstand and the remaining safety margin from the ultimate limit state under the current working condition, thereby enhancing the reliability of design and on-site decision-making. Furthermore, based on the allowable gravity amplification factor, the target dataset, and the load-displacement curve, the safe strength elastoplastic results and high-risk areas are determined, enabling refined management of local yielding. This avoids the overly conservative approach of immediately deeming the structure unqualified upon yielding, while ensuring the overall structural safety. Finally, based on the high-risk areas and pre-defined reinforcement rules, reinforcement schemes are derived, avoiding modifications to the structure based on experience and improving the targetedness and efficiency of reinforcement design.

[0149] In some implementations, please refer to Figure 2 Static nonlinear solutions are performed based on fundamental parameters, element partitioning, and conditional constraints to obtain the target dataset and load-displacement curves. This process may include the following steps:

[0150] S210. Based on the gravity amplification factor and unit partitioning under the current working conditions, determine the equivalent inertial force.

[0151] Specifically, the stress conditions of the target structure in various engineering stages—such as static self-weight, lifting, transportation, and extreme accident assumptions—are uniformly abstracted into different gravity amplification factors. For example, the gravity amplification factor is 1 under the static self-weight condition; the gravity amplification factor is 1.5 or 2.0 under the dynamic conditions during lifting or transportation. Based on the current condition, the corresponding gravity amplification factor is determined. The equivalent gravitational acceleration experienced by the target structure is determined based on the corresponding gravity amplification factor under the current condition. Then, based on the mass of the unit partition and the equivalent gravitational acceleration experienced by the target structure, the equivalent inertial force is determined.

[0152] For example, the formula for calculating the equivalent gravitational acceleration acting on the target structure is shown below:

[0153]

[0154] in, Equivalent gravitational acceleration under operating conditions (unit: m / s²) 2 ); This is the gravitational amplification factor (dimensionless). Indicates the self-weight condition. Indicates a hypergravity condition; The standard gravitational acceleration is typically taken as 9.81 m / s². 2 .

[0155] The formula for calculating the equivalent inertial force applied to each unit partition is shown below:

[0156]

[0157] in, For the first Equivalent inertial force on each unit partition (unit: N); For the first Mass of each unit partition (unit: kg); Equivalent gravitational acceleration under operating conditions (unit: m / s²) 2 ).

[0158] S220. Based on the equivalent inertial force, perform elastic analysis to determine the elastic response results.

[0159] S230. When the elastic response results indicate insecurity, static nonlinear solutions are performed based on basic parameters, element partitioning, and condition constraints to obtain the target dataset and load-displacement curves.

[0160] Specifically, after determining the application of the equivalent inertial force, an elastic analysis is first performed to obtain the elastic response results of the structure under this load, including stress and deformation. If the elastic analysis results indicate that the local or overall response of the structure exceeds the allowable range (e.g., stress exceeds the yield limit or deformation exceeds the allowable value), an elastoplastic analysis is further conducted to evaluate the load-bearing capacity and deformation behavior of the structure after entering the plastic state, thereby comprehensively verifying its safety and reliability under various working conditions. Therefore, when the elastic response results indicate unsafety, a static nonlinear solution is performed based on the foundation parameters, element partitioning, and condition constraints to obtain the target dataset and load-displacement curves for subsequent elastoplastic analysis.

[0161] In the above implementation, the equivalent inertial force is determined based on the gravity amplification factor and element partitioning corresponding to the current working condition. Elastic analysis is then performed based on the equivalent inertial force to determine the elastic response result. If the elastic response result indicates an unsafe condition, static nonlinear solution is performed based on the basic parameters, element partitioning, and condition constraints to obtain the target dataset and load-displacement curve, providing a data foundation for subsequent elastoplastic analysis and strength verification.

[0162] In some implementations, please refer to Figure 3 The basic parameters include the thickness data of each component. Obtaining the unit partition can include the following steps:

[0163] S310. Based on actual function, stress characteristics and geometry, the target structure is divided into partitions to obtain the basic structure partitions.

[0164] Specifically, using a 3D model of the target structure, the various parts of the target structure are defined based on their actual function, stress characteristics, and geometric shape: their main functions are clarified (e.g., overall support, hoisting, reinforcement, or transition); the types of loads they typically bear are analyzed (e.g., uniformly distributed loads, concentrated forces, predominantly tension and bending loads, or localized stress concentrations); and their shape and thickness characteristics are observed (whether they are thin plates, have large cross-section stiffeners, perforated lifting lugs, or have sharp corners or steps, etc.). Based on this, the target structure is divided into different regions, resulting in basic structural zoning, so that appropriate strength, deformation, and plastic strain evaluation standards can be applied to each region subsequently.

[0165] For example, taking the cold shield structure of a tokamak as an example, it can be divided into several basic structural areas according to its actual function, stress characteristics, and geometry. The area whose actual function is mainly to cover and bear load, belonging to a large-area plate-like load-bearing area, whose stress characteristics are mainly distributed loads caused by overall compression, overall bending, and self-weight, with less concentrated point loads, and whose geometry is a thin and uniform plate thickness without large holes or drastic thickness changes, exhibiting a continuous plate structure, is classified as a "large area, thin thickness, relatively uniform stress, and geometrically continuous plate-like area," and defined as the cold shield thin-walled panel area. In addition to the cold shield thin-walled panel area, the tokamak cold shield structure can also be divided into zones according to their corresponding actual function, stress characteristics, and geometry, resulting in the lug and its support connection area, the stiffener and its connection area with the panel, the weld transition area, and the geometric abrupt change area. The cold shield thin-walled panel area, the lug and its support connection area, the stiffener and its connection area with the panel, the weld transition area, and the geometric abrupt change area serve as the basic structural zones.

[0166] It should be noted that if other similar special areas (such as special opening areas, locally thickened step areas, complex corner areas, etc.) appear in actual projects, they can also be divided into a separate zone according to the same principle and included in the basic structure zone.

[0167] S320. Based on the thickness data and geometric features of each component, the basic structure partition is divided into unit types to obtain unit partitions.

[0168] Specifically, geometric features mainly encompass the following aspects: whether it is a thin-plate structure (thickness much smaller than length and width); whether it is a relatively thick, blocky solid; whether it is a slender member (length much larger than cross-sectional dimensions); whether the main stress forms are large bending, torsion, or tension and compression; whether the connection method is rigid, hinged, or flexible; and whether there are geometric discontinuities such as openings, steps, or abrupt angles. Based on these features, it can be determined whether shell elements, solid elements, or beam / rod elements should be used for modeling. Therefore, using the 3D model of the target structure, combined with the thickness data and geometric features of each component, the appropriate element type is selected for the basic structure partitioning, and then the element regions are divided to establish a finite element model. It should be noted that using a hybrid modeling method combining shell elements, solid elements, and beam / rod elements can control the number of units while also considering overall stiffness and local stress accuracy.

[0169] For example, the basic structural partitions may include the cold-screen thin-walled panel area, the lug and its support connection area, the stiffener and its connection area with the panel, the weld transition area, and the geometric abrupt change area as basic structural partitions. The cold-screen thin-walled panel area can be modeled using shell elements (e.g., Shell elements), with the thickness assigned as a parameter. Thick solid areas such as lugs and supports are modeled using solid elements (e.g., Solid elements) to more precisely describe stress concentration areas such as hole edges and roots; slender members such as stiffeners and their connection areas with the panel are modeled using beam or rod elements, with section parameters expressed as follows. The mesh is connected to the panel via node coupling or constraints; the mesh is locally refined in and around the weld transition zone. There are generally two ways to handle the weld transition zone: if the area around the weld transition zone is a thin plate structure and a very fine weld shape is not required, shell elements can be used, and the mesh can be appropriately refined around the weld transition zone; if the geometry around the weld transition zone changes drastically, or the local stress is particularly critical, solid elements can be used locally, and the weld transition zone and transition fillets can be made into a solid model.

[0170] In the above embodiments, the target structure is partitioned based on actual function, stress characteristics and geometry to obtain basic structure partitions. Based on the thickness data and geometric features of each component, the basic structure partitions are divided into unit types to obtain unit partitions, which provides a basis for subsequent determination of safety strength elastoplastic results.

[0171] In some implementations, please refer to Figure 4 The basic parameters include the true stress-true strain curve for each material. Obtaining each true stress-true strain curve may include the following steps:

[0172] S410. Obtain the engineering stress-engineering strain curve for each material in the target structure.

[0173] S420. Based on the engineering stress-engineering strain curve corresponding to each material, the actual stress-actual strain curve corresponding to each material is obtained by conversion.

[0174] Specifically, after determining the material grade corresponding to a particular material, its corresponding engineering stress-strain curve can be obtained by querying and matching based on that grade. It is important to note that the engineering stress-strain curve is calculated based on the original gauge length and original cross-sectional area of ​​the specimen. After significant plastic deformation of the material, because the change in cross-sectional area is not considered, the curve gradually deviates from the actual mechanical response of the material. Therefore, to more accurately reflect the mechanical behavior of the material under large deformation, especially in the plastic stage, the engineering stress-strain data needs to be converted into true stress-true strain. First, the entire curve or several representative points need to be selected from the engineering stress-strain curve. These selected points should effectively reflect the material's performance under different stress states. Next, the corresponding conversion formula is used to convert these engineering stress-strain data into true stress-true strain data. The engineering stress-strain curve can be derived from the original data measured by a material testing machine or from test data tables provided in material handbooks or standard specifications.

[0175] For example, the formula for converting an engineering stress-strain curve into a true stress-strain curve is shown below:

[0176] (1) Actual stress:

[0177]

[0178] in, This represents the actual stress, expressed in MPa. This refers to engineering stress, expressed in MPa. For engineering strain, dimensionless (mm / mm).

[0179] (2) Realistic Response:

[0180]

[0181] in, For realistic response, dimensionless; For engineering strain, dimensionless (mm / mm).

[0182] In the above implementation, the engineering stress-engineering strain curve corresponding to each material in the target structure is obtained. Based on the engineering stress-engineering strain curve corresponding to each material, the actual stress-actual strain curve corresponding to each material is obtained, thereby improving the accuracy of the data and providing a data foundation for subsequent finite element analysis.

[0183] In some implementations, please refer to Figure 5 Static nonlinear solutions are performed based on fundamental parameters, element partitioning, and conditional constraints to obtain the target dataset and load-displacement curves. This process may include the following steps:

[0184] S510. Based on basic parameters, element partitioning and condition constraints, static nonlinear solution is performed to obtain the overall maximum displacement of the target structure, the maximum equivalent stress of the material position structure and the maximum equivalent plastic strain of the key area corresponding to each load step.

[0185] The material location structure can be a logical or physical decomposition and division of a complex overall target structure by comprehensively considering the material properties (such as material, strength, density, function, etc.) and spatial location information (such as relative orientation, layout, connection relationship, topology, etc.) of the target structure. Critical areas can be local locations within the target structure that, due to their mechanical state, geometric features, or material properties, become potential weak points, most prone to irreversible plastic deformation or damage, and thus have a decisive impact on the safety, lifespan, and performance of the entire structure; examples include lifting lugs, supports, and welds.

[0186] Specifically, the input data for the finite element analysis model includes basic parameters, element partitions, and condition constraints. In the static nonlinear solution process of the finite element analysis model, the initial gravity amplification factor is used... Start (can be taken from the corresponding heavy working condition) , also desirable or ), to fix the step size (For example, 0.1g or 0.05g) Load in increments until the structure shows obvious yielding or the solution fails to converge, eventually reaching the termination factor. A series of load steps are obtained. By integrating the solution data, a set of structural response data covering "from light load to heavy load" is output, and the overall maximum displacement of the target structure, the stress components corresponding to the material location structure, and the maximum equivalent plastic strain in the key area corresponding to each load step are extracted from it. Then, according to the stress components and equivalent stress calculation formulas corresponding to the material location structure, the maximum equivalent stress of the material location structure corresponding to each load step is obtained. Among them, the overall maximum displacement of the target structure (unit: mm) is used as a deformation index; the maximum equivalent stress of the material location structure (unit: MPa) is used as a strength index; and the maximum equivalent plastic strain in the key area (dimensionless) is used as a plastic development index.

[0187] For example, the formula for calculating the equivalent stress of the material location structure is as follows:

[0188]

[0189] in, Equivalent stress at material location and structure (unit: MPa); , , The normal stress components are in the x, y, and z directions (unit: MPa). , , The shear stress components (unit: MPa) are shown in the corresponding plane.

[0190] S520. Based on the maximum overall displacement of the target structure corresponding to each load step, pairing is performed to obtain the load-displacement curve.

[0191] Specifically, the maximum overall displacement of the target structure corresponding to each load step is paired with that load step (i.e., the gravity amplification factor) to obtain a series of data points. With the maximum overall displacement of the target structure as the abscissa and the load step (i.e., the gravity amplification factor) as the ordinate, the series of data points are connected according to the functional relationship obtained from the elastoplastic simulation to form a load-displacement curve, which reflects the changing trend of the overall stiffness of the structure as deformation increases.

[0192] For example, the formula for obtaining the load-displacement curve is shown below:

[0193]

[0194] in, For the load step (i.e., the gravity amplification factor, which is dimensionless). The maximum overall displacement of the target structure (unit: mm); The function relationship is obtained from elastoplastic simulation and has no explicit analytical expression.

[0195] In the above implementation, static nonlinear solutions are performed based on basic parameters, unit partitions, and condition constraints to obtain the maximum overall displacement of the target structure, the maximum equivalent stress of the material position structure, and the maximum equivalent plastic strain of the key area corresponding to each load step. Based on the maximum overall displacement of the target structure corresponding to each load step, the load-displacement curves are obtained to identify the evolution process of the target structure from the elastic stage to the plastic stage, thereby giving the corresponding plastic ultimate bearing capacity and the maximum allowable working condition after conversion.

[0196] In some implementations, please refer to Figure 6 Determining the allowable gravity amplification factor based on the load-displacement curve may include the following steps:

[0197] S610. Based on the load-displacement curve, determine the slope of the curve in the elastic stage.

[0198] S620. Based on the slope of the curve, reduction factor and load-displacement curve in the elastic stage, determine the gravity amplification factor of the plastic limit.

[0199] S630. Based on the plastic limit gravity amplification factor and the safety reduction factor, determine the allowable gravity amplification factor.

[0200] Specifically, since structures typically undergo elastic and plastic stages during stress, analysis based on their load-displacement curves is necessary. First, starting from the initial small load end of the load-displacement curve, the load-displacement relationship is approximated as a straight line, and the fitting range is gradually expanded. When the curve significantly deviates from the straight line and exceeds the engineering allowable error limit, the preceding segment is defined as the elastic stage. Linear regression is performed on the data within this interval to obtain the slope of the elastic stage curve. Subsequently, a reduction factor (e.g., 0.5) is determined according to established rules (such as the "twice the elastic slope method)," and a reference line is established in conjunction with the slope of the elastic stage curve. The gravity amplification factor corresponding to the intersection of this reference line and the load-displacement curve is the plastic limit gravity amplification factor of the target structure. Based on this, a safety reduction factor is further introduced, and finally, the allowable gravity amplification factor corresponding to the target structure is calculated based on the plastic limit gravity amplification factor and the safety reduction factor.

[0201] For example, based on the load-displacement curve, the slope of the curve in the elastic stage is obtained by linear regression. The formula is shown below:

[0202]

[0203] in, The slope of the curve in the elastic phase is 1 / mm; This is the change in the gravitational amplification factor within the elastic segment (dimensionless). This represents the maximum displacement change within the elastic segment (unit: mm).

[0204] Using elastic slope Draw an "elastic reference line" through the origin; then draw a line with a slope of... Reference lines ( (This is the reduction factor). The slope is... The gravitational amplification factor corresponding to the intersection of the reference line and the load-displacement curve is used as the gravitational amplification factor for the plastic limit.

[0205] The formula for calculating the gravitational amplification factor of the plastic limit is as follows:

[0206]

[0207] in, is the plastic limit gravitational amplification factor (dimensionless); The rules for determining limit points are based on specifications or engineering agreements.

[0208] It should be noted that the criteria for determining the limit point according to specifications or engineering agreements mean that after obtaining the load-displacement curve, the load value corresponding to the ultimate bearing capacity is not arbitrarily specified, but rather the limit position on the curve is determined based on the existing criteria in the applicable design specifications or internal engineering technical agreements. These criteria may include a significant decrease in stiffness, displacement reaching a specified limit, or plastic deformation reaching an allowable threshold, etc.

[0209] Based on specifications or design requirements, the plastic ultimate bearing capacity is reduced to obtain the permissible gravity amplification factor for the allowable working condition. The formula is as follows:

[0210]

[0211] in, Allowable gravitational amplification factor (dimensionless); The safety reduction factor (dimensionless). It is determined by standards or engineering experience; It is the plastic limit gravitational amplification factor (dimensionless).

[0212] It should be noted that in practical engineering, equivalent analysis is usually performed by adjusting the gravitational acceleration. The plastic limit gravitational acceleration refers to the maximum equivalent gravity level that a cold shield can withstand, provided that a certain degree of controllable plastic deformation is allowed while the overall structure remains in a safe state. The main purposes of determining this value are: firstly, to quantitatively provide the upper limit of the structure's load-bearing capacity, which can be used to calculate the maximum allowable gravitational acceleration under various working conditions, and thus calculate the safety margin; secondly, to provide a clear design basis for selecting hoisting and transportation conditions and for necessary structural reinforcement, thereby avoiding overly conservative designs or designs that exceed the actual load-bearing capacity of the structure. The formula for determining the plastic limit gravitational acceleration is shown below:

[0213]

[0214] in, Plastic limit gravitational acceleration (unit: m / s²) 2 ); is the plastic limit gravitational amplification factor (dimensionless); Standard gravitational acceleration (unit: m / s²) 2 ).

[0215] In the above embodiments, the slope of the elastic stage curve is determined based on the load-displacement curve. Based on the slope of the elastic stage curve, the reduction factor, and the load-displacement curve, the plastic limit gravity amplification factor is determined. Based on the plastic limit gravity amplification factor and the safety reduction factor, the allowable gravity amplification factor is determined, providing a data basis for subsequent overall and local safety strength elastoplastic results.

[0216] In some implementations, please refer to Figure 7 The safety strength elastoplastic result includes the safety result and the strength elastoplastic result. Based on the allowable gravity amplification factor, the target dataset, and the load-displacement curve, the safety strength elastoplastic result is determined, which may include the following steps:

[0217] S710. Based on the allowable gravity amplification factor and the gravity amplification factor under actual working conditions, a safety result is obtained.

[0218] Specifically, based on the actual working conditions, the gravity amplification factor under those conditions is obtained. The ratio of the allowable gravity amplification factor to the actual gravity amplification factor is calculated to obtain the safety factor, which reflects the ratio between the structural resistance and the actual applied load. Based on the safety factor, a safety assessment can be further conducted to obtain safety results. For example, when the safety factor is greater than 1, it can be determined that the cold shield strength meets the safety requirements under that working condition. In other implementations, the safety margin can also be calculated using the safety factor, i.e., safety margin = safety factor. 1. Based on the size of the safety margin, the structural safety can be quantitatively assessed, and a safety result can be obtained.

[0219] For example, the formula for calculating the safety factor is as follows:

[0220]

[0221] in, Safety factor (dimensionless); Allowable gravitational amplification factor (dimensionless); This is the gravity amplification factor (dimensionless) under actual working conditions.

[0222] It should be noted that the gravity amplification factor under actual working conditions can be obtained mainly through the following methods:

[0223] 1. Based on the dynamic load factor given in the hoisting or transportation plan:

[0224] Lifting plans, transportation plans, or internal company lifting specifications usually clearly specify the value of the dynamic load factor, such as "lifting conditions adopt ×× dynamic load factor" or "transportation conditions are considered based on ×× times gravity". If the plan specifies "lifting is considered based on 1.3 times gravity", then the gravity amplification factor under actual working conditions is taken as 1.3.

[0225] 2. Refer to the recommended values ​​in relevant design specifications:

[0226] Standards in fields such as nuclear engineering, pressure vessels, and lifting machinery often provide recommended ranges for gravity amplification factors. For example:

[0227] Normal hoisting conditions: 1.1~1.3.

[0228] Transportation or impact conditions: 1.3 to 1.5 (or higher).

[0229] When designing a project, a suitable value can be selected within this range as the gravity amplification factor under this working condition.

[0230] 3. Based on the equipment manual or data provided by the manufacturer:

[0231] Technical documents for lifting and transportation equipment sometimes explicitly list information such as "maximum acceleration" and "recommended dynamic load factor." This data can be used to calculate the corresponding gravity amplification factor.

[0232] 4. Use actual measurement data:

[0233] If an accelerometer is installed on site and the maximum acceleration during hoisting or transportation is measured (a_measured), then the gravity amplification factor can be directly calculated as: a_measured / g (standard gravity).

[0234] S720. Based on the gravity amplification factor under actual working conditions and the target structure's overall maximum displacement, material position structure's maximum equivalent stress, and key area's maximum equivalent plastic strain corresponding to each load step, determine the target structure's overall maximum displacement, material position structure's maximum equivalent stress, and key area's maximum equivalent plastic strain under actual working conditions.

[0235] Specifically, the load step corresponding to the gravity amplification factor under actual working conditions is determined from the load step set, and this is taken as the target load step. Then, based on the target load step, the maximum overall displacement of the target structure, the maximum equivalent stress of the material location structure, and the maximum equivalent plastic strain of the key area corresponding to each load step are queried to determine the maximum overall displacement of the target structure, the maximum equivalent stress of the material location structure, and the maximum equivalent plastic strain of the key area corresponding to the target load step, and these are taken as the maximum overall displacement of the target structure, the maximum equivalent stress of the material location structure, and the maximum equivalent plastic strain of the key area under actual working conditions.

[0236] S730. Based on the target structure's overall maximum displacement, material position structure's maximum equivalent stress, and key area's maximum equivalent plastic strain under actual working conditions, the strength-elastic-plastic results are obtained.

[0237] Specifically, the strength-elasticity results include overall strength assessment results, material location strength results, and elastoplastic results. The allowable deformation threshold is determined based on design documents or relevant specifications. This threshold typically limits the maximum displacement or deformation of the entire structure under specific load conditions, aiming to ensure the structure's normal functionality, durability, and perceived safety during service. The maximum overall displacement of the target structure under actual load conditions is compared with the allowable deformation threshold to determine whether the design requirements are met, thus obtaining the overall strength assessment result. If the maximum overall displacement of the target structure under actual load conditions is less than or equal to the allowable deformation threshold, the structure is considered to meet the design requirements in terms of deformation. If the maximum overall displacement of the target structure under actual load conditions is greater than the allowable deformation threshold, it indicates that the structural deformation is excessive, which may affect safety or use, requiring design review or reinforcement.

[0238] The allowable factor and yield stress of the material are given based on material information, design documents, or relevant specifications. The yield strength of the material is determined by multiplying the yield stress and the allowable factor. The maximum equivalent stress at the material location is then compared with the yield strength to determine if the maximum equivalent stress is within an acceptable range, thus obtaining the strength result for that location. If the maximum equivalent stress at the material location is less than or equal to the yield strength, the stress level at that location is considered acceptable, and the structural strength meets the requirements. If the maximum equivalent stress at the material location is greater than the yield strength, the stress at that location exceeds the allowable range, and the structural strength does not meet the requirements.

[0239] For example, the formula for comparing the maximum equivalent stress at a material location structure with the material's yield strength is shown below:

[0240]

[0241] in, The maximum equivalent stress at the material location structure (unit: MPa); This is the allowable factor (dimensionless); The yield stress of the material (unit: MPa). This indicates the yield strength of the material.

[0242] The allowable plastic deformation limit for the critical area is determined based on one of the following methods: design specifications or industry standards, material properties and test data, internal project agreements, or experience. Then, the maximum equivalent plastic strain in the critical area is compared with the allowable plastic deformation limit, while observing whether the plastic area is confined to the geometric discontinuity zone of the critical area to determine the elastoplastic result. If the maximum equivalent plastic strain in the critical area is less than or equal to the allowable plastic deformation limit and the plastic area is controlled near the geometric discontinuity zone without large-scale expansion, the yielding of the critical area can be considered "controllable," with limited impact on the overall structural safety. Conversely, if the maximum equivalent plastic strain in the critical area exceeds the allowable plastic deformation limit, it means the critical area may face the risk of excessive plastic deformation, requiring further assessment or appropriate measures.

[0243] In some implementations, the determination of allowable plastic deformation limits for critical areas is primarily based on design specifications or industry standards. For example, relevant specifications for nuclear engineering, pressure vessels, or structural design typically provide recommended ranges. In engineering practice, the recommended values ​​from these specifications can be directly adopted, or slightly conservatively adjusted, as the allowable plastic deformation limits for critical areas.

[0244] In other implementations, the allowable plastic deformation limit for critical areas is determined based on material properties and experimental data. Materials possess a certain degree of ductility, and experiments can reveal the approximate range of plastic deformation they can withstand before cracking or severe damage. In engineering practice, a ratio much smaller than the material's actual ultimate plastic strain capacity is typically chosen as the safe and acceptable allowable plastic deformation limit for critical areas.

[0245] In some implementation methods, the allowable plastic deformation limits for critical areas are determined based on internal project agreements or engineering experience. If the same organization has completed projects with similar structures and materials, a set of internal practices often develops. For example, it may stipulate that the plastic strain at the root of the lifting lug must not exceed a certain percentage, or that the plastic strain in the weld transition zone must not exceed a specific value.

[0246] In the above embodiments, a safety result is obtained based on the allowable gravity amplification factor and the gravity amplification factor under actual working conditions. Based on the gravity amplification factor under actual working conditions and the maximum overall displacement of the target structure, the maximum equivalent stress of the material position structure, and the maximum equivalent plastic strain of the key area corresponding to each load step, the maximum overall displacement of the target structure, the maximum equivalent stress of the material position structure, and the maximum equivalent plastic strain of the key area under actual working conditions are determined. Based on the maximum overall displacement of the target structure, the maximum equivalent stress of the material position structure, and the maximum equivalent plastic strain of the key area under actual working conditions, the strength elastoplastic result is obtained, thereby achieving a more accurate elastoplastic assessment of the target structure.

[0247] In some implementations, please refer to Figure 8 Identifying high-risk areas based on the target dataset can include the following steps:

[0248] S810. Based on the gravity amplification factor under actual working conditions and the maximum equivalent plastic strain of the key area corresponding to each load step, determine the maximum equivalent plastic strain of the key area under actual working conditions.

[0249] S820. Based on the maximum equivalent plastic strain in the key area under actual working conditions and the corresponding local plastic strain risk threshold in the key area, high-risk areas are determined.

[0250] Specifically, the local plastic strain risk threshold for critical areas is pre-determined based on specifications, material testing, and engineering experience. The load step corresponding to the gravity amplification factor under actual working conditions is determined from the load step set and used as the target load step. Then, based on the target load step, the maximum equivalent plastic strain in the critical area corresponding to each load step is queried to determine the maximum equivalent plastic strain in the critical area corresponding to the target load step, and this is used as the maximum equivalent plastic strain in the critical area under actual working conditions. The maximum equivalent plastic strain in the critical area under actual working conditions is compared with the local plastic strain risk threshold corresponding to the critical area. If the maximum equivalent plastic strain in the critical area is greater than the local plastic strain risk threshold, the critical area is identified as a high-risk area. The local plastic strain risk threshold corresponding to the critical area is less than or equal to the allowable plastic deformation limit of the critical area.

[0251] In some implementations, in addition to comparing the maximum equivalent plastic strain in the critical area under actual working conditions with the corresponding local plastic strain risk threshold, the following two aspects can also be combined for high-risk area assessment: first, the extent of the plastic strain influence; and second, the importance of the area in the overall structure. For example, if the maximum equivalent plastic strain in a certain area is close to or exceeds the corresponding local plastic strain risk threshold, and the plastic strain distribution is significantly concentrated in the critical load-bearing parts, then the area can be determined to be a high-risk area.

[0252] It should be noted that the local plastic strain risk threshold corresponding to the critical area is less than or equal to the allowable plastic deformation limit of the critical area. The local plastic strain risk threshold for the critical area is equivalent to an "alarm line," while the allowable plastic deformation limit of the critical area is equivalent to a "red line." The alarm line must be set before the red line so that potentially high-risk areas can be identified in advance through the local plastic strain risk threshold. Therefore, the local plastic strain risk threshold is usually taken as a certain percentage of the allowable plastic deformation limit of the critical area (e.g., slightly lower than the allowable plastic deformation limit of the critical area). When the local response reaches or exceeds the local plastic strain risk threshold, the area is considered to be an object requiring special attention or priority reinforcement; while the allowable plastic deformation limit of the critical area itself is still the final basis for determining whether the code or design requirements are met.

[0253] In the above implementation, based on the gravity amplification factor under actual working conditions and the maximum equivalent plastic strain of the critical area corresponding to a load step, the maximum equivalent plastic strain of the critical area under actual working conditions is determined. Based on the maximum equivalent plastic strain of the critical area under actual working conditions and the local allowable equivalent plastic strain limit corresponding to the critical area, high-risk areas are identified, providing a basis for subsequent updates to the scheme.

[0254] In some implementations, the data obtained from elastoplastic analysis and strength verification under multiple working conditions (such as schematic diagrams of cold shield structures, finite element model diagrams, stress cloud diagrams, plastic strain cloud diagrams, and load-displacement curves) are combined to construct a clear and consistent basis for engineering decision-making.

[0255] Specifically, after completing the elastoplastic analysis and strength verification under multiple working conditions, the key result data for each load step and each working condition are automatically extracted through post-processing scripts or interface programs. These data mainly include: gravity amplification factor. The corresponding maximum displacement The corresponding maximum equivalent stress Maximum equivalent plastic strain in key regions Safety margin for corresponding operating conditions .

[0256] Based on the aforementioned key results data, a cold screen multi-condition analysis results database is constructed. This database supports unified storage and comparison of analysis results under different design schemes and different conditions. Key results data for each analysis and each condition are stored in structured record format. Each record may contain the following fields: condition identifier ID (e.g., "self-weight condition", "lifting condition 1", "lifting condition 2", etc.), analysis version number or timestamp, gravity amplification factor, displacement, stress, plastic strain, allowable value and safety margin, and structural parameter version (e.g., plate thickness, lifting lug size, stiffener arrangement scheme number).

[0257] Furthermore, based on common data visualization tools or a self-developed interface, the following analytical functions can be implemented using this database:

[0258] 1. For selected working conditions, automatically plot the "gravity amplification factor - maximum displacement" curve and the "gravity amplification factor - safety margin" curve.

[0259] 2. Select several operating conditions for comparison and overlay the curves of different operating conditions on the same graph.

[0260] 3. Automatically mark risky operating conditions based on screening criteria (such as "safety margin is below a certain threshold").

[0261] 4. Display the minimum safety margin of a design scheme under all operating conditions.

[0262] By constructing this multidimensional database and its visualization interface, the load-bearing capacity and safety margin of the cold screen under various working conditions can be intuitively evaluated without the need for manual processing of a large amount of simulation data, thereby improving application efficiency and visualization level.

[0263] In some implementations, please refer to Figure 9 The method may also include the following steps:

[0264] S910. Summarize the data based on the target dataset to obtain the operating condition curve and envelope.

[0265] S920, based on operating condition curves and envelopes, obtains results for scheme selection and safety assessment.

[0266] Specifically, to comprehensively assess the load-bearing capacity of a cold-faced structure, it is necessary to compile target datasets under various operating conditions (such as assembly, self-weight, lifting, transportation, and extreme accidents), including data such as gravity amplification factor, maximum displacement, maximum equivalent stress, and plastic strain in key areas, and calculate the corresponding safety margins. Based on this data, operating condition curves and envelopes can be plotted. Operating condition curves: An independent curve is plotted for each operating condition, such as the "self-weight operating condition curve," "lifting operating condition curve," and "transportation operating condition curve." Envelopes: Based on all operating condition curves, the most unfavorable results (such as minimum safety margin, maximum displacement, etc.) under the same gravity amplification factor are connected to form the overall load-bearing capacity envelope. This envelope is typically plotted using coordinates such as "gravity amplification factor - safety margin" or "gravity amplification factor - maximum displacement," which can visually display the structure's response boundaries under different load levels.

[0267] Based on the operating condition curves and envelopes, by comparing the actual gravity amplification factor with the allowable gravity amplification factor for each operating condition, the distance from the ultimate limit state (i.e., the safety margin) can be directly assessed, yielding results for scheme selection and safety assessment. For example, this can guide the selection of hoisting schemes, optimize the design and layout of temporary supports, and support operational safety assessments.

[0268] In the above implementation, data is aggregated based on the target dataset to obtain operating condition curves and envelopes. Based on the operating condition curves and envelopes, results are obtained for scheme selection and safety assessment, thereby improving the safety of the target structure's operation.

[0269] In some implementations, please refer to Figure 10 The method may also include the following steps:

[0270] S1010, Measure the maximum displacement and gravity amplification factor of the target structure under actual working conditions.

[0271] S1020. Based on the parameters to be calibrated, a combination of constituent parameters is obtained.

[0272] S1030. Based on the maximum displacement, gravity amplification factor, and parameter vector, an error function is constructed.

[0273] S1040. Based on the error function, determine the target parameter vector and perform elastoplastic analysis and strength verification under multiple working conditions according to the target parameter vector.

[0274] Specifically, for the target structure, the maximum displacement and dynamic amplification factor under actual working conditions are first obtained through experimental loading or on-site monitoring. Then, based on engineering experience, parameters that significantly affect the simulation results and have uncertainties are selected as parameters to be calibrated, and these are combined into a parameter vector. Based on this, an error function is constructed according to the maximum displacement, dynamic amplification factor, and parameter vector. The parameter vector that minimizes the error function is determined as the target parameter vector. Finally, the model is updated using the target parameter vector, and elastoplastic analysis under multiple working conditions is performed again to complete the strength verification.

[0275] For example, the response data of a cold screen under actual load can be obtained in any of the following ways:

[0276] 1. Test loading: Perform loading tests on the cold screen sample or its local structure, and record the displacement or strain of several characteristic points under different load levels.

[0277] 2. On-site monitoring: During the equipment installation or trial operation phase, displacement gauges, strain gauges or three-dimensional measurement points are placed at key locations on the cold shield to monitor and record its actual response.

[0278] The measurement data can be recorded as: the first At each measuring point, under load level Displacement below or strain .

[0279] Based on engineering experience, parameters that significantly affect the simulation results and have uncertainties are selected as parameters to be calibrated, such as the material yield stress correction factor. Material strengthening parameters, such as strain hardening modulus correction factor The parameters related to boundary conditions, such as support stiffness and contact stiffness, are used to form a parameter vector. .

[0280] Based on the difference between the simulation results and the measurement data, an error function is constructed:

[0281]

[0282] in, The error function is dimensionless or has the same dimension as the square of the displacement. For parameters are At that time, the first Each measuring point, load level The displacement obtained from the simulation is in mm; This corresponds to the measured displacement; , which is a weighting coefficient, dimensionless.

[0283] Optimization algorithms (such as gradient method, genetic algorithm, and other numerical optimization methods) are used to find the error function. and use it as the target parameter vector. .

[0284] target parameter vector It is applied to elastoplastic analysis and strength verification under multiple working conditions, and re-executes multi-working-condition analysis, plastic ultimate bearing capacity determination and strength verification.

[0285] In the above implementation, by introducing measured data to invert and calibrate the elastoplastic constitutive parameters and boundary conditions, the accuracy and reliability of the simulation results can be effectively improved without changing the overall analysis process.

[0286] In some implementations, please refer to Figure 11 The method may also include the following steps:

[0287] S1110. Based on the target structure, determine the design variables to be calibrated.

[0288] S1120. Based on the design variables to be calibrated, constraints, and objective function, determine the target design variables and update the target structure based on the target design variables.

[0289] Specifically, a parametric modeling method is used for the target structure to establish a corresponding reinforcement design template. This template defines the key geometric parameters affecting the structural strength and stiffness as design variables to be calibrated, forming a vector of design variables to be calibrated. Under the premise of satisfying all given constraints, the design variable vector is optimized using an objective function to ultimately obtain the target design variables that meet safety requirements. After determining the target design variables, the parametric model is updated based on these variables to complete the reinforcement design of the target structure.

[0290] For example, parametric modeling is performed on the cold screen structure, and key geometric parameters affecting the structural strength and stiffness are defined as design variables to be calibrated, including: the thickness of the cold screen panel. Thickness of the lifting lug plate and dimensions such as height and width, and cross-sectional dimensions of reinforcing ribs. and spacing Weld transition fillet radius etc. The above-mentioned design variables to be calibrated are combined into a vector of design variables to be calibrated. .

[0291] By using parametric modeling tools or scripts, the design variables mentioned above can be associated with the geometric features, element properties, and material properties of the finite element model. This enables the model to automatically update geometry, adjust element properties, match corresponding materials, and automatically remesh and solve when the design variable values ​​change, thus efficiently supporting subsequent iterative adjustments and optimizations.

[0292] Based on structural safety and deformation control, the following constraints are set:

[0293] 1. Safety margins under various operating conditions .

[0294] 2. Maximum displacement .

[0295] 3. Equivalent plastic strain in key regions .

[0296] The optimization objective can be set as one of the following forms or a weighted combination of multiple objectives:

[0297] 1. Minimize the total mass of the structure.

[0298] 2. Minimize the maximum displacement under specific working conditions.

[0299] 3. Perform a weighted combination between mass and deformation.

[0300]

[0301] in, The objective function is... Total mass of the cold shield structure (unit: kg); Maximum displacement (unit: mm); , , which is the weighting coefficient (dimensionless).

[0302] Using suitable optimization algorithms (such as genetic algorithms, particle swarm optimization, gradient optimization, etc.), a design scheme that satisfies the constraints is searched in the design variable space, and the response is calculated by continuously calling the elastoplastic analysis and strength verification methods under multiple working conditions.

[0303] Through multiple iterations, one or more optimized design schemes that meet safety requirements are obtained. For each scheme, key information such as design variable values, safety margins for each operating condition, and quality is recorded, allowing engineers to make the final selection based on factors such as manufacturing cost, schedule, and process feasibility.

[0304] The design variable values ​​corresponding to the selected optimization scheme are used as target design variables. These target design variables, as input, are substituted back into the parameterized cold screen structure model, which drives the automatic updating of the 3D geometric model, finite element model, and related properties. This generates a detailed design of the target structure that is completely consistent with the optimization results, guiding subsequent manufacturing and production.

[0305] In the above implementation, based on the target structure, the design variables to be calibrated are determined. Based on the design variables to be calibrated, the constraints, and the objective function, the target design variables are determined, and the target structure is updated based on the target design variables. This realizes an integrated improvement process of "simulation-optimization-verification" and improves design efficiency and the optimality of results.

[0306] This specification provides a method for elastoplastic analysis and strength verification under multiple working conditions. For an example, please refer to [link to example description]. Figure 12 The analysis focuses on the cold shield of a tokamak device, clearly defining the analysis object and requirements. The evaluation conditions include assembly, lifting, transportation, operation, and extreme conditions. Geometric and material information for the cold shield is collected, including the dimensions, arrangement, and material properties of the panel, lifting lugs, stiffeners, supports, and welds. Then, based on function and stress characteristics, the cold shield is divided into key areas such as the panel area, lifting lug area, stiffener area, and weld and geometric abrupt change area. Next, a hybrid element finite element model of the cold shield is established, using shell elements for the panel, solid elements for the lifting lugs and supports, and beam or rod elements for the stiffeners, with appropriate connection relationships established. Loads and boundary conditions are defined for each condition, unifying the conditions at different stages to different gravity levels or acceleration levels, and setting lifting point constraints and temporary support conditions.

[0307] Determine whether it is necessary to calibrate the model using experimental data or field measurement data.

[0308] If necessary, utilize displacement and strain data obtained from experiments or field measurements to adjust material parameters and support stiffness, ensuring the simulation results closely approximate the measured results, thus completing model calibration. Perform elastoplastic nonlinear analysis on each working condition, gradually increasing the load to extract the overall maximum displacement, maximum stress, and plastic strain in key areas under each condition. If not necessary, directly perform elastoplastic nonlinear analysis on each working condition, gradually increasing the load to extract the overall maximum displacement, maximum stress, and plastic strain in key areas under each condition.

[0309] Next, determine whether the overall stiffness meets the requirements under each working condition and whether the plastic strain in the key areas is within the allowable range.

[0310] If the conditions are outside the permissible range, high-risk identification should be performed for the non-compliant working conditions and areas. Reinforcement solutions should be proposed, such as thickening the plates, adjusting the lifting lug dimensions, optimizing the arrangement of stiffeners, and improving weld transitions, to update the cold shield structure. Based on the updated cold shield structure, a hybrid element finite element model of the cold shield should be established, using shell elements for the panels, solid elements for the lifting lugs and supports, and beam or rod elements for the stiffeners, with appropriate connection relationships established.

[0311] If it is within the allowable range, determine whether there is an optimization need such as weight reduction, material saving, or further improvement of stiffness.

[0312] If optimization is required, a parametric model is established, with panel thickness, lifting lug dimensions, stiffener cross-sections and spacing, and weld transition forms as adjustable parameters. The model automatically searches for optimal solutions under constraints that meet strength and deformation requirements. Then, elastoplastic nonlinear analysis is performed on each working condition, gradually increasing the load to extract the overall maximum displacement, maximum stress, and plastic strain in key areas for each condition.

[0313] If there is no need for optimization, under the final determined cold shield design scheme, summarize the displacement, stress, plastic strain, and safety margin results for each working condition to form a multi-working-condition load-bearing capacity envelope and safety margin distribution. Then determine whether it is necessary to centrally manage the results of multiple rounds of analysis.

[0314] If it is necessary to centrally manage the results of multiple rounds of analysis, a multidimensional database can be established to automatically import key results from each analysis and generate load-bearing capacity curves and safety margin comparison charts in a visualization interface for engineers to query and analyze. This will generate a final engineering report and conclusions, summarizing the load-bearing capacity of the cold shield under multiple working conditions, the analysis results of high-risk areas, and reinforcement and optimization recommendations, providing a basis for hoisting plans, structural approvals, and project archiving.

[0315] If it is not necessary to centrally manage the results of multiple rounds of analysis, the final engineering report and conclusions can be generated directly, summarizing the load-bearing capacity of the cold shield under multiple working conditions, the analysis results of high-risk areas, and the reinforcement and optimization suggestions, providing a basis for hoisting schemes, structural approvals, and engineering archiving.

[0316] This specification provides a multi-condition elasto-plastic analysis and strength verification device 1300. Please refer to [link to relevant documentation]. Figure 13 The multi-condition elastoplastic analysis and strength verification device 1300 includes: a target structure data acquisition module 1310, a static nonlinear solution module 1320, an allowable gravity amplification factor determination module 1330, an analysis result and risk area determination module 1340, and a reinforcement scheme generation module 1350.

[0317] The target structure data acquisition module 1310 is used to acquire the basic parameters, unit partitions and condition constraints of the target structure.

[0318] The static nonlinear solution module 1320 is used to perform static nonlinear solution based on the basic parameters, the element partitioning and the condition constraints, and obtain the target dataset and load-displacement curves.

[0319] The permissible gravity amplification factor determination module 1330 is used to determine the permissible gravity amplification factor based on the load-displacement curve;

[0320] The analysis results and risk area determination module 1340 is used to determine the safety strength elastoplastic results and high-risk areas based on the allowable gravity amplification factor, the target dataset, and the load-displacement curve;

[0321] The reinforcement scheme generation module 1350 is used to obtain a reinforcement scheme based on the high-risk area and preset reinforcement rules.

[0322] For a detailed description of the device for elastoplastic analysis and strength verification under multiple working conditions, please refer to the description of the method for elastoplastic analysis and strength verification under multiple working conditions above, which will not be repeated here.

[0323] In some embodiments, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 14As shown, the computer device includes a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements a method for elastoplastic analysis and strength verification under multiple operating conditions. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0324] Those skilled in the art will understand that Figure 14 The structures shown are merely block diagrams of some structures related to the solutions disclosed in this specification, and do not constitute a limitation on the computer device to which the solutions disclosed in this specification are applied. Specifically, the computer device may include more or fewer components than shown in the figures, or combine certain components, or have different component arrangements.

[0325] In some embodiments, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method steps described above.

[0326] This specification provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method in any of the above embodiments.

[0327] One embodiment of this specification provides a computer program product including instructions that, when executed by a processor of a computer device, enable the computer device to perform the steps of the method described in any of the above embodiments.

[0328] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). In addition, computer-readable media can even be paper or other suitable media on which programs can be printed, because programs can be obtained electronically, for example, by optically scanning paper or other media, followed by editing, interpreting or otherwise processing as necessary, and then stored in computer memory.

Claims

1. A method for elastoplastic analysis and strength verification under multiple working conditions, characterized in that, The method includes: Obtain the basic parameters, element partitions, and condition constraints of the target structure; Based on the basic parameters, the element partitions, and the conditional constraints, a static nonlinear solution is performed to obtain the target dataset and load-displacement curves. This includes: determining the equivalent inertial force based on the gravity amplification factor corresponding to the current working condition and the element partitions; performing elastic analysis based on the equivalent inertial force to determine the elastic response result; and, if the elastic response result indicates an unsafe condition, performing a static nonlinear solution based on the basic parameters, the element partitions, and the conditional constraints to obtain the target dataset and load-displacement curves. Based on the load-displacement curve, determine the allowable gravity amplification factor; Based on the allowable gravity amplification factor, the target dataset, and the load-displacement curve, the safety strength elastoplastic results and high-risk areas are determined. Based on the high-risk areas and the preset reinforcement rules, a reinforcement scheme is obtained.

2. The method according to claim 1, characterized in that, The basic parameters include the thickness data of each component, and the acquisition of unit partitions includes: The target structure is divided into partitions based on its actual function, stress characteristics, and geometry to obtain the basic structure partitions. Based on the thickness data and geometric features of each component, the basic structure partition is divided into unit types to obtain the unit partition.

3. The method according to claim 1, characterized in that, The basic parameters include the true stress-true strain curve for each material. Obtaining each true stress-true strain curve includes: Obtain the engineering stress-engineering strain curves for each material in the target structure; Based on the engineering stress-engineering strain curve corresponding to each material, the true stress-true strain curve corresponding to each material is obtained by conversion.

4. The method according to claim 1, characterized in that, The step of performing static nonlinear solution based on the basic parameters, the element partitioning, and the condition constraints to obtain the target dataset and load-displacement curves also includes: Based on the aforementioned basic parameters, unit partitioning, and conditional constraints, a static nonlinear solution is performed to obtain the overall maximum displacement of the target structure, the maximum equivalent stress of the material location structure, and the maximum equivalent plastic strain of the key area corresponding to each load step. The load-displacement curve is obtained by pairing the target structure's overall maximum displacement corresponding to each load step.

5. The method according to claim 4, characterized in that, The determination of the allowable gravity amplification factor based on the load-displacement curve includes: Based on the load-displacement curve, determine the slope of the curve in the elastic stage; Based on the slope of the elastic stage curve, the reduction factor, and the load-displacement curve, the plastic limit gravity amplification factor is determined. The permissible gravity amplification factor is determined based on the plastic limit gravity amplification factor and the safety reduction factor.

6. The method according to claim 5, characterized in that, The safety strength elastoplastic result includes a safety result and a strength elastoplastic result. Determining the safety strength elastoplastic result based on the allowable gravity amplification factor, the target dataset, and the load-displacement curve includes: The safety result is obtained based on the allowable gravity amplification factor and the gravity amplification factor under actual working conditions; Based on the gravity amplification factor under actual working conditions and the target structure's overall maximum displacement, material position structure's maximum equivalent stress, and key area's maximum equivalent plastic strain corresponding to each load step, the target structure's overall maximum displacement, material position structure's maximum equivalent stress, and key area's maximum equivalent plastic strain under actual working conditions are determined. Based on the target structure's overall maximum displacement, the material position structure's maximum equivalent stress, and the key area's maximum equivalent plastic strain under the actual working conditions, the strength-elastic-plastic results are obtained.

7. The method according to claim 4, characterized in that, Based on the target dataset, high-risk areas are identified, including: Based on the gravity amplification factor under actual working conditions and the maximum equivalent plastic strain in the key area corresponding to each load step, the maximum equivalent plastic strain in the key area under actual working conditions is determined. Based on the maximum equivalent plastic strain in the key area under the actual working conditions and the corresponding plastic strain risk threshold, high-risk areas are determined.

8. The method according to claim 1, characterized in that, The method further includes: Based on the target dataset, data is aggregated to obtain operating condition curves and envelopes; Based on the operating condition curve and the envelope, results are obtained for scheme selection and safety assessment.

9. The method according to claim 1, characterized in that, The method further includes: Measure the maximum displacement and gravity amplification factor of the target structure under actual working conditions; The parameters to be calibrated are combined to obtain a vector of constituent parameters. An error function is constructed based on the maximum displacement, the gravity amplification factor, and the parameter vector; Based on the error function, the target parameter vector is determined, and elastic-plastic analysis and strength verification under multiple working conditions are performed based on the target parameter vector.

10. The method according to claim 1, characterized in that, The method further includes: Based on the target structure, determine the design variables to be calibrated; Based on the design variables to be calibrated, constraints, and objective function, the target design variables are determined, and the target structure is updated based on the target design variables.

11. A device for elastoplastic analysis and strength verification under multiple working conditions, characterized in that, The device includes: The target structure data acquisition module is used to acquire the basic parameters, cell partitions, and condition constraints of the target structure. The static nonlinear solution module is used to perform static nonlinear solutions based on the basic parameters, the element partitions, and the conditional constraints to obtain the target dataset and load-displacement curves. This includes: determining the equivalent inertial force based on the gravity amplification factor corresponding to the current working condition and the element partitions; performing elastic analysis based on the equivalent inertial force to determine the elastic response result; and, if the elastic response result indicates an unsafe condition, performing static nonlinear solutions based on the basic parameters, the element partitions, and the conditional constraints to obtain the target dataset and load-displacement curves. The permissible gravity amplification factor determination module is used to determine the permissible gravity amplification factor based on the load-displacement curve. The analysis results and risk area determination module is used to determine the safety strength elastoplastic results and high-risk areas based on the allowable gravity amplification factor, the target dataset, and the load-displacement curve; The reinforcement scheme generation module is used to obtain a reinforcement scheme based on the high-risk area and preset reinforcement rules.

12. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 10.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 10.

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