Method for simulating and safety evaluation of hoisting multi-working condition of tokamak large components

Abstract

This invention belongs to the field of hoisting technology and discloses a multi-condition dynamic simulation and safety assessment method for hoisting large components of a tokamak. The method includes: establishing a hoisting system simulation model; defining each working condition in the hoisting process and applying corresponding dynamic displacement or load boundary conditions to the hoisting system simulation model according to each working condition; using explicit dynamics or transient dynamics methods to solve the time history integral of each working condition of the hoisting system simulation model to obtain the time history data of stress, displacement, attitude, and tension at each lifting point of the hoisted component under each working condition; performing envelope analysis on the time history data of stress, displacement, attitude, and tension at each lifting point of the hoisted component under each working condition to extract the stress envelope, tension envelope, attitude deviation envelope, and minimum safety factor of the hoisted component under each working condition, and identifying risks for each working condition in the hoisting process; and generating a hoisting risk identification report based on the risk identification results of each working condition in the hoisting process.

Description

Technical Field

[0001] This invention relates to the field of hoisting technology, and in particular to a method for multi-condition dynamic simulation and safety assessment of hoisting large components of a tokamak. Background Technology

[0002] As the core experimental platform for controlled nuclear fusion research, the tokamak device consists of large and complex components such as a vacuum chamber, superconducting magnet, cold shield, and supporting frame. These components typically weigh tens to hundreds of tons each, have complex geometries, and require extremely small installation gaps, placing extremely high demands on the attitude control precision and structural safety during the hoisting process.

[0003] Currently, the hoisting of components during the final assembly stage of tokamak devices mainly relies on experience-based design and quasi-static finite element analysis methods. Existing analyses are mostly based on static or quasi-static assumptions, considering only the component's self-weight and simplified load distribution at lifting points. They fail to accurately reflect the nonlinear dynamic effects caused by factors such as lifting acceleration, braking deceleration, inertial oscillation, flexible sling tension, and collision buffering during hoisting, leading to the following shortcomings: First, the structural response is underestimated, making it impossible to capture the peak stress time history and posing a risk of misjudging the safety margin; second, attitude changes are not considered, making it difficult to predict component attitude deviations and hoisting path deviations; third, multi-condition comprehensive evaluation is lacking, with a lack of superposition and limit envelope evaluation mechanisms for multiple stages of conditions such as acceleration, constant speed, braking, and buffering; fourth, hoisting risk prediction methods are insufficient, with process parameters relying heavily on manual experience, making it difficult to form a quantitative risk assessment system based on simulation data. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one objective of this invention is to propose a multi-condition dynamic simulation and safety assessment method for hoisting large components of a tokamak, which can effectively improve the safety margin and reliability of hoisting schemes.

[0005] To achieve the above objectives, a first aspect of the present invention proposes a method for multi-condition dynamic simulation and safety assessment of lifting large components of a tokamak. The method includes: establishing a lifting system simulation model, which includes a model of the lifted component, a model of the balance beam and cable-stayed mechanism, and a model of the slings; defining various conditions during the lifting process, and applying corresponding dynamic displacement or load boundary conditions to the lifting system simulation model according to each condition. These conditions include lifting acceleration, constant speed, braking deceleration, swinging, and buffer collision conditions; and employing explicit dynamic simulation. The simulation model of the hoisting system is solved by time history integration using dynamic or transient dynamic methods to obtain time history data of stress, displacement, attitude, and tension at each lifting point of the hoisted component under each working condition. Envelope analysis is performed on the time history data of stress, displacement, attitude, and tension at each lifting point of the hoisted component under each working condition to extract the stress envelope, tension envelope, attitude deviation envelope, and minimum safety factor of the hoisted component under each working condition, so as to identify risks in each working condition of the hoisting process. Based on the risk identification results of each working condition of the hoisting process, a hoisting risk identification report is generated.

[0006] The tokamak large component hoisting multi-condition dynamic simulation and safety assessment method according to embodiments of the present invention establishes a dynamic model including the hoisted component, balance beam, cable-stayed mechanism and slings, and defines multiple typical conditions such as lifting acceleration, constant speed, braking deceleration, swinging and buffer collision, which can realistically reflect the dynamic response of the entire hoisting process and overcome the shortcomings of traditional static analysis in capturing the peak value of inertial load and attitude change. Through explicit or transient dynamic time history solution and multi-condition envelope analysis, stress envelope, lifting point tension envelope, attitude deviation envelope and minimum safety factor can be extracted to realize limit state assessment and risk identification under multiple conditions superimposed. Finally, a hoisting risk identification report is automatically generated, providing a quantitative safety assessment basis for the hoisting process design of large tokamak components, and effectively improving the safety margin and reliability of the hoisting scheme.

[0007] In addition, the tokamak large component hoisting multi-condition dynamic simulation and safety assessment method according to the above embodiments of the present invention may also include the following additional technical features: According to an embodiment of the present invention, the establishment of the hoisting system simulation model includes: establishing the hoisted component model as a flexible body model; setting rigid body reference points, and coupling the sling model, the balance beam model and the hoisted component model through the rigid body reference points to form a rigid-flexible coupled overall model, so as to realize the synchronous response of rigid body motion and flexible deformation.

[0008] According to one embodiment of the present invention, the relationship between axial force and strain in the sling model is as follows:

[0009] in, The axial tension of the sling For engineering strain strain rate The equivalent cross-sectional area of ​​the sling Initial length of the sling Initial equivalent elastic modulus Secondary equivalent elastic modulus Equivalent viscous damping coefficient Stage-boundary strain This is the ultimate strain.

[0010] According to one embodiment of the present invention, in the lifting acceleration condition, the constant speed condition, and the braking deceleration condition, the applied dynamic displacement or load boundary conditions are as follows:

[0011]

[0012] in, This refers to the vertical displacement of the lifting point or the suspended component. For lifting speed, For lifting acceleration, For maximum lifting acceleration, For maximum braking deceleration, For the maximum uniform speed, To accelerate the end time of the segment, The time at the end of the uniform speed segment. This is the end time of the braking phase. This is a time variable used temporarily during the integration process.

[0013] According to one embodiment of the present invention, in the buffer collision condition, the applied dynamic displacement or load boundary condition is:

[0014] And the energy absorbed during the buffering process must satisfy:

[0015]

[0016] in, To buffer force, For compression amount, For compression rate, The stiffness coefficient of the buffer element. The damping coefficient is... The kinetic energy of the hoisting system at the moment of braking. For safety reasons, The total mass of the hoisted system. The instantaneous velocity of the suspension point at the initial moment of braking.

[0017] According to one embodiment of the present invention, in the oscillating condition, the applied dynamic displacement or load boundary condition is:

[0018] or

[0019] in, This refers to the lateral displacement of the lifting point or component. This represents the maximum lateral displacement caused by the initial disturbance or perturbation. The angular frequency of the external excitation. This refers to the lateral displacement of the suspended component or lifting point relative to its equilibrium position. , These are lateral acceleration and velocity, respectively. This represents the ratio of system damping to critical damping. The system's natural angular frequency, External lateral disturbance force, For the equivalent quality of the system.

[0020] According to an embodiment of the present invention, when using the explicit dynamic solution, the time step is... The following conditions must be met:

[0021]

[0022] in, For safety reasons, The feature length of the unit. For material wave velocity, The elastic modulus of the material, The density of the material.

[0023] According to one embodiment of the present invention, the risk identification report includes the coordinates of the dangerous node, the dangerous moment, the working condition input information, and the risk level.

[0024] According to an embodiment of the present invention, the method further includes: setting multiple sets of different combinations of hoisting process parameters, and simulating each set of hoisting process parameter combinations to obtain multiple sets of simulation result samples; establishing a response surface model based on the multiple sets of simulation result samples, and back-optimizing the hoisting process parameters according to the response surface model to obtain the optimal combination of hoisting process parameters that satisfies safety constraints and attitude accuracy indicators.

[0025] According to one embodiment of the present invention, the lifting point tension envelope is used for sling and lifting point load verification, the attitude deviation envelope is used to determine attitude stability and installation risk, and the stress envelope and the minimum safety factor are used to determine high-risk areas related to structural strength.

[0026] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] Figure 1 This is a flowchart illustrating the multi-condition dynamics simulation and safety assessment method for hoisting large components of a tokamak according to an embodiment of the present invention. Detailed Implementation

[0028] 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.

[0029] The following describes, with reference to the accompanying drawings, a method for multi-condition dynamic simulation and safety assessment of the hoisting of large components of a tokamak according to an embodiment of the present invention.

[0030] Figure 1 This is a flowchart illustrating the method for multi-condition dynamic simulation and safety assessment of the hoisting of large components of a tokamak according to an embodiment of the present invention.

[0031] Specifically, such as Figure 1 As shown, the multi-condition dynamics simulation and safety assessment method for hoisting large components of a tokamak includes: S101, Establish a simulation model of the hoisting system. The hoisting system simulation model includes the model of the hoisted component, the model of the balance beam and the cable-stayed mechanism, and the model of the sling.

[0032] Specifically, in this embodiment, the hoisting system simulation model is established for a tokamak device, and step S101 further includes the following sub-steps: (1) Establish the model of the suspended component: Import the three-dimensional geometric data of the suspended component (such as vacuum chamber sector, magnet module or cold screen assembly) from CAD or survey model, delete non-load-bearing decorative structures, and retain only key load-bearing parts such as stiffeners, flanges, lifting lugs, and connecting plates. A hybrid modeling method of shell elements and solid elements is adopted to ensure the accuracy of overall stiffness and local stress distribution. The material constitutive model adopts an elastoplastic model, including bilinear, multilinear kinematic hardening models or Chaboche kinematic hardening models, and gives the yield strength, elastic modulus of each segment and hardening parameters.

[0033] (2)Establish the model of the balance beam and the cable-stayed mechanism: The balance beam is discretized using beam elements or shell elements, and the cable-stayed mechanism such as the stay rod is discretized using beam elements, truss elements or rod-spring combination elements to accurately simulate its axial bearing and bending stiffness characteristics.

[0034] (3)Establish the sling model: The sling and the cable-stayed cable are modeled using axial spring elements or three-dimensional truss elements (truss elements), and their mechanical behavior is described using a piecewise non-linear spring-damping axial constitutive model. The input parameters include the initial length L0 of the sling, the equivalent cross-sectional area A, the non-linear moduli E1 and E2, the piecewise threshold strains ε1 and ε2, and the damping coefficient c. s Among them, the sling includes a sling belt and a steel cable.

[0035] (4)Connection and contact definition: The hanging point is constrained by a hinge or a universal coupling; the contact relationship is defined between the component and the hanging ear and the liner plate, including the friction coefficient μ, and the equivalent connection method of bolts or welds is used; the surface-to-surface contact is set between the lifted component and the surrounding tooling or buffer block, and the contact stiffness k n and the tangential friction coefficient μ are defined.

[0036] S102, Define each working condition during the hoisting process, and apply the corresponding dynamic displacement or load boundary conditions to the hoisting system simulation model according to each working condition. Each working condition includes the hoisting acceleration condition, the uniform speed condition, the braking deceleration condition, the swinging condition and the buffer collision condition.

[0037] Specifically, in this embodiment, the entire hoisting process is divided into five typical stages according to the actual process sequence. An independent load change curve (control curve) is defined for each stage and loaded into the model: (1)Hoisting acceleration, uniform speed and braking deceleration conditions: The vertical motion curve z(t) of the hanging point is defined by displacement control, and a three-segment S-shaped speed curve is used to smoothly simulate the hoisting and braking processes of the crane, so that the acceleration is smoothly transitioned to avoid inertial impact.

[0038] The relationship between the vertical speed of the hanging point and time is: In the acceleration section (0 ≤ t < t1), ; In the uniform speed section (t1 ≤ t < t2), ; In the braking section (t2 ≤ t < t3), ; The displacement curve is obtained by integrating the speed: ; Among them, among them, is the vertical displacement of the hanging point or the lifted component, is the hoisting speed, is the maximum hoisting acceleration. For maximum braking deceleration, For the maximum uniform speed, To accelerate the end time of the segment, The time at the end of the uniform speed segment. This is the end time of the braking phase. This is a time variable used temporarily during the integration process.

[0039] (2) Buffer Collision Condition: When the suspended component or lifting device approaches the support point or limit block, a nonlinear spring-damped contact model is defined to simulate the buffer energy absorption process. The buffer force is:

[0040] And the energy absorbed during the buffering process must satisfy:

[0041]

[0042] in, To buffer force, For compression amount, For compression rate, The stiffness coefficient of the buffer element. The damping coefficient is... The kinetic energy of the hoisting system at the moment of braking. For safety reasons, The total mass of the hoisted system. The instantaneous velocity of the suspension point at the initial moment of braking.

[0043] (3) Swinging condition: The lateral motion of the hoisting system is described by the dynamic equation of a simple pendulum:

[0044] or

[0045] in, This refers to the lateral displacement of the lifting point or component. This represents the maximum lateral displacement caused by the initial disturbance or perturbation. The angular frequency of the external excitation (such as wind, driving disturbance), This refers to the lateral displacement of the suspended component or lifting point relative to its equilibrium position, i.e., the lateral swing offset. , These are lateral acceleration and velocity, respectively. This represents the ratio of system damping to critical damping. The system's natural angular frequency, It is the acceleration due to gravity. For equivalent hanging length, External lateral disturbance force, For the equivalent quality of the system.

[0046] S103 uses explicit dynamics or transient dynamics methods to solve the time history integral of the hoisting system simulation model under each working condition, and obtains the time history data of the stress, displacement, attitude and tension of each hoisting point of the hoisted component under each working condition.

[0047] Specifically, in this embodiment, when using an explicit dynamics solver to perform time history integration for each working condition, the time step satisfies:

[0048] in, The safety factor (generally taken as 0.8-0.9) is dimensionless. The element characteristic length is expressed in meters (m). Let be the material wave velocity, expressed in m / s. Its simplified calculation formula is as follows:

[0049] in, This refers to the elastic modulus of the material, expressed in Pa. This represents the density of the material, expressed in kg / m³.

[0050] It should be noted that during the time history integration process, the input conditions include, but are not limited to, the mass and moment of inertia of each component of the hoisting system (the hoisted component, the balance beam, the slings, and the cable-stayed mechanism), the connection and contact definitions (such as the friction coefficient and contact stiffness), and the dynamic displacement or load boundary conditions applied for each working condition in step S102. The solver performs time history integration under these conditions and directly outputs the time history data of stress, displacement, attitude, and tension at each hoisting point, such as the equivalent stress field at each moment, the tension at each hoisting point, and the attitude angle vector of the hoisted component.

[0051] S104 performs envelope analysis on the time history data of stress, displacement, attitude, and tension at each lifting point of the suspended component under various working conditions. It extracts the stress envelope, tension envelope at each lifting point, attitude deviation envelope, and minimum safety factor of the suspended component under various working conditions to identify risks in each working condition of the lifting process.

[0052] Specifically, in this embodiment, the formula for calculating the stress envelope is:

[0053] The formula for calculating the envelope of the tension force at the suspension point is:

[0054] The formula for calculating the attitude deviation envelope is:

[0055] in, This is the position vector of any point in the model, used to describe the variation of stress distribution with space, in meters (m). The working condition number indicates different lifting stages, such as acceleration, braking, swinging, and collision. This represents any moment in the simulation time history, expressed in seconds. In working conditions and time Below, position The material stress intensity at the specified location, expressed in MPa; The maximum stress envelope value is the maximum stress value at a certain point across all operating conditions and times, used to identify critical locations, and is expressed in MPa. In working conditions and time Next, the The tensile force at the suspension point, measured in N; For the maximum tensile force envelope value, in all working conditions and times, the first... The maximum tensile force at the lifting point is used for selection and verification, and the unit is N; This is the component attitude angle vector, representing the rotation angle of the suspended component, typically including the yaw angle. Pitch angle Twist angle The unit is rad; The maximum attitude deviation envelope value represents the maximum deviation of attitude change under all operating conditions. It is used to determine attitude stability and is measured in rad.

[0056] The formula for calculating the minimum safety factor is:

[0057] in, This represents the allowable stress of the material, expressed in MPa. In working conditions and time Below, position The material stress intensity at the specified location, expressed in MPa; This represents the minimum safety factor.

[0058] like If a risk is detected at a specific location or time, the system determines that there is a risk at that location or time. Finally, the system automatically summarizes the envelope analysis results, generating stress cloud maps, attitude change animations, and critical moment markers, achieving three-dimensional dynamic visualization of the hoisting path and providing intuitive and quantitative decision-making basis for hoisting safety assessment.

[0059] S105, Based on the risk identification results of each working condition during the hoisting process, generate a hoisting risk identification report.

[0060] Specifically, in this embodiment, based on the hazardous areas, hazardous moments, and minimum safety factor determination results identified by the envelope analysis in step S104, the system automatically generates a structured lifting risk identification report. This report includes the following core contents: ① Hazardous node coordinates, i.e., the specific location information on the lifted component determined to be high-risk; ② Hazardous moments, i.e., the specific time step and corresponding working condition number for each high-risk state; ③ Working condition input information, including lifting process parameters such as lifting acceleration, braking deceleration, sling configuration, and buffer parameters used in this simulation, to trace the causes of risk; ④ Risk level, defined and graded based on the minimum safety factor (e.g., ...). <1.0 indicates high risk, 1.0≤ <1.5 indicates medium risk. ≥1.5 indicates low risk); ⑤ The stress change curve and attitude change curve at the corresponding time point intuitively show the structural response evolution process before and after the risk occurs.

[0061] Furthermore, in some embodiments of the present invention, establishing a hoisting system simulation model includes: establishing the hoisted component model as a flexible body model; setting rigid body reference points, and coupling the sling model, the balance beam model, and the hoisted component model through the rigid body reference points to form a rigid-flexible coupled overall model, so as to achieve synchronous response of rigid body motion and flexible deformation.

[0062] Specifically, in this embodiment, the suspended component is modeled using a hybrid shell element and solid element model, defined as a flexible body, possessing realistic stiffness and mass distribution characteristics, used to accurately calculate the stress-strain time history and local deformation throughout the lifting process; the balance beam is modeled using beam element or shell element model, defined as a flexible or equivalent flexible rod, used to transmit the lifting point force and couple the vibration response; the slings and stay cables are modeled using axial spring element or three-dimensional element model, defined as nonlinear spring or cable element model, used to simulate the tensile deformation and damping energy dissipation effect of the flexible lifting device.

[0063] The lifting point (i.e., the point of action of the hook or main crane) is set as a rigid body reference point in the finite element software. This reference point has six spatial degrees of freedom, representing the macroscopic motion input driven by the crane. Through coupling constraints, the motion of the rigid body reference point is associated with the positions of each lifting point on the lifted component, as well as the nodal degrees of freedom of flexible components such as slings and balance beams connecting the two, forming an overall degree of freedom coupling. The rigid-flexible coupled overall model constructed in this way can simultaneously solve the macroscopic rigid body motion driven by the crane (such as lifting and braking) and the elastic deformation and local vibration of flexible components under the same dynamic framework, accurately reflecting the dynamic transmission and mutual influence between inertial forces, elastic deformation, and lifting point motion in large and complex lifting systems.

[0064] Furthermore, in some embodiments of the present invention, the correspondence between axial force and strain in the sling model is as follows:

[0065] in, Axial force (axial tension) is the axial tension of the sling, measured in N. It is the actual tension generated by the sling along its length and is the main component of the load transmitted by the lifting system. For engineering strain, dimensionless, it is the ratio of the sling elongation to the original length. Strain rate, measured in 1 / s, represents the rate of change of strain over time and is used to describe the rate effect during dynamic loading. This refers to the equivalent cross-sectional area of ​​the sling, expressed in m², and is taken as the effective load-bearing cross-sectional area of ​​the wire rope, sling, or chain. This is the initial length of the sling, expressed in meters (m), which is the static length before hoisting (the natural length when not under tension). The initial equivalent elastic modulus (softening stage) corresponds to the equivalent modulus in the small strain zone (relaxation stage), reflecting the initial tensile stiffness of the material, and is expressed in MPa. This is the secondary equivalent elastic modulus (hardening stage), corresponding to the modulus in the larger strain zone (fully stressed stage), reflecting the stiffness of the sling after it enters the linear or hardened zone, and its unit is MPa. The equivalent viscous damping coefficient describes the energy dissipation capacity of a sling under dynamic tension. Its value can be obtained experimentally or empirically, and its unit is N*s / m. The stage-bound strain (softening → hardening transition point) represents the strain value at which the stress-strain curve transitions from the initial stage to the secondary stiffness stage; it is dimensionless. Ultimate strain (failure strain) is the strain of the sling when it reaches the maximum allowable tension. If this value is exceeded, the sling enters the fracture or irreversible damage zone.

[0066] It should be noted that the sling model can be directly implemented in Abaqus / Explicit or ANSYS TransientDynamics using a custom spring element (Connector / COMBIN39 / MPC Spring), and the parameter values ​​can be obtained through experimental fitting (tensile test or dynamic load test). For example, if the sling is made of steel wire rope, typical values ​​are: ≈80-100GPa, ≈160-200GPa, ≈0.002-0.005, ≈0.02-0.03. If the sling is made of synthetic fiber, the typical value is: ≈1-5GPa, ≈10-15GPa, ≈0.01-0.03, ≈0.10-0.15.

[0067] Furthermore, in some embodiments of the present invention, the applied dynamic displacement or load boundary conditions in the lifting acceleration condition, constant speed condition, and braking deceleration condition are as follows:

[0068]

[0069] in, This represents the vertical displacement of the lifting point or the lifted component, relative to the initial lifting position (upward is positive), in meters (m). Here, represents the lifting speed (the first derivative of displacement with respect to time), and represents the instantaneous lifting speed of the lifting device or lifting point, expressed in m / s. Maximum lifting acceleration, the upper limit of the allowable acceleration of the crane or motor system, used during the acceleration phase, and measured in m / s². This refers to the maximum braking deceleration, the deceleration amplitude during the hoisting braking phase, used for the braking section, and is measured in m / s². This is the maximum uniform speed, the upper limit of the speed during the stabilization phase of takeoff, expressed in m / s. This is the end time of the acceleration phase, in seconds. The time at the end of the uniform velocity segment is expressed in seconds. The braking section ends at the moment the hoisting stops, measured in seconds. This is a time variable used temporarily during the integration process.

[0070] Furthermore, in some embodiments of the present invention, the applied dynamic displacement or load boundary conditions in the buffer collision condition are as follows:

[0071] And the energy absorbed during the buffering process must satisfy:

[0072]

[0073] in, The buffer force is the reaction force generated by a buffer pad, damping block, or support component during compression, measured in N (newtons). This refers to the compression amount, the instantaneous deformation of the cushioning element (rubber pad, air bladder, hydraulic cylinder), expressed in meters (m). The compression rate is the first derivative of the compression with respect to time, used in the damping term, and is expressed in m / s. This is the stiffness coefficient of the buffer element, which, in conjunction with the exponent n, controls the nonlinear stiffness. If n=1, it is the linear stiffness. The unit is N / m. The damping coefficient is the energy dissipation component related to the control speed, with units of N*s / m. The kinetic energy of the hoisting system at the moment of braking is expressed in J. For safety margins, it is typically 1.2-1.5. The total mass of the hoisted system includes the total mass of components, lifting gear, and balance beam, expressed in kg. The instantaneous velocity of the suspension point at the initial braking moment is expressed in m / s.

[0074] Furthermore, in some embodiments of the present invention, the applied dynamic displacement or load boundary conditions in the oscillating condition are as follows:

[0075] or

[0076] in, This refers to the lateral displacement of the lifting point or component, that is, the lateral offset relative to the vertical equilibrium position, measured in meters (m). This represents the maximum lateral displacement caused by the initial disturbance or perturbation, i.e., the swing amplitude, in meters (m). The angular frequency of external excitation (such as wind, driving disturbance), expressed in rad / s. This refers to the lateral displacement of the suspended component or lifting point relative to its equilibrium position, i.e., the lateral swing offset. , Let represent lateral acceleration and velocity, respectively, and let represent the inertia and damping terms in the dynamic equation, with units of m / s² and m / s, respectively. This is the ratio of the system's damping to its critical damping, typically taken as 0.01-0.05, and is dimensionless. Let be the system's natural angular frequency, expressed in rad / s, and its calculation formula is as follows:

[0077] in, Let gravitational acceleration be 9.81 m / s². The equivalent lifting length is the distance from the lifting point to the center of mass of the component, expressed in meters (m). External lateral disturbance force, in N. The equivalent mass of the system includes the suspended components and the counterweight beam, and is expressed in kg.

[0078] Furthermore, in some embodiments of the present invention, when using explicit dynamics for solving, the time step is... The following conditions must be met:

[0079]

[0080] in, The safety factor (typically 0.8-0.9) is dimensionless. The characteristic length of the element, in meters. For material wave velocity, This refers to the elastic modulus of the material, expressed in Pa. This represents the density of the material, expressed in kg / m³.

[0081] Furthermore, in some embodiments of the present invention, the risk identification report includes the coordinates of the hazardous node, the critical moment, the working condition input information, and the risk level, and integrates the stress and attitude change curves at the corresponding moment, facilitating designers to quickly locate the source of risk and make targeted improvements. In addition, the present invention does not specifically limit the content included in the risk identification report.

[0082] Furthermore, in some embodiments of the present invention, the method further includes: setting multiple sets of different hoisting process parameter combinations, and simulating each set of hoisting process parameter combinations to obtain multiple sets of simulation result samples; establishing a response surface model based on the multiple sets of simulation result samples, and back-optimizing the hoisting process parameters according to the response surface model to obtain the optimal hoisting process parameter combination that satisfies safety constraints and attitude accuracy indicators.

[0083] Specifically, in this embodiment, firstly, the main process control parameters affecting hoisting safety and efficiency are defined as editable input variables, forming an input vector X. These hoisting process parameters include, but are not limited to: Maximum lifting acceleration (m / s^2) Maximum braking deceleration (m / s^2) Maximum uniform speed (m / s) Braking time (s) : No. The equivalent length (m) of the sling. : Angle of stay / Angle of support (rad) , Equivalent modulus of sling / cable segment (MPa) : Damping coefficient of the suspension cable (N*s / m) : Stiffness coefficient of buffer element (N / m) Nonlinear exponent of buffer element stiffness (dimensionless). Damping coefficient of buffer element (N*s / m). : Contact / friction coefficient (dimensionless). The names, default values, allowable ranges, and unit descriptions of the above variables are uniformly managed through parameterized template files. The script reads the template and automatically generates multiple sets of simulation input files with different parameter combinations in batches.

[0084] This allows for batch simulation and sample acquisition. For each combination of hoisting process parameters, the system automatically submits the solution to execute the complete multi-condition hoisting simulation process (i.e., steps S101 to S104), obtaining the corresponding simulation response output, which forms the output vector Y. The output vector Y includes, but is not limited to, […]. Limiting equivalent stress envelope (MPa) : No. Maximum axial force envelope at the lifting point (N). Attitude deviation envelope (rad) : Lifting completion time (s). This forms a training sample set consisting of N sets of input-output pairs. , where n = 1 to N.

[0085] Based on the aforementioned training sample set, a mapping model between hoisting process parameters and simulation response output is established. For example, this mapping model can employ a quadratic response surface model or a machine learning-based surrogate model. The polynomial expression for the quadratic response surface model is:

[0086] in, For the first One output, For the first One input, For constant terms, The coefficient of the linear term, The coefficient of the squared term, The cross term coefficient, The total number of input variables. For the j-th input variable, For the i-th input variable, This represents the interaction term between the i-th and j-th input variables. Before modeling, the input variables can be dimensionless to improve fitting accuracy and numerical stability.

[0087] Based on the actual hoisting process requirements, optimization constraints are set, including safety constraints (such as the maximum structural stress being less than the allowable material stress, and the minimum safety factor being greater than or equal to 1.0 or a specified safety threshold) and attitude accuracy indicators (such as the maximum attitude deviation angle being less than the allowable limit of the installation gap). On this basis, with the optimization objectives of maximizing the safety factor and minimizing the hoisting completion time, the Pareto multi-objective optimization algorithm is used to optimize the quadratic response surface model, automatically obtaining the optimal combination of hoisting process parameters that satisfies both safety constraints and attitude accuracy indicators.

[0088] The optimal parameter combination obtained from the optimization solution is automatically updated back to the parameterized template file, which can then be directly used in subsequent hoisting simulations of similar components. Through the above closed-loop optimization process, this invention can transform the complex hoisting process design from a trial-and-error mode relying on human experience to a quantitative optimization mode based on simulation data, significantly shortening the iteration cycle of hoisting schemes and effectively avoiding potential safety hazards caused by experience-based parameter settings.

[0089] Furthermore, in some embodiments of the present invention, the lifting point tension envelope is used for sling and lifting point load verification, the attitude deviation envelope is used to determine attitude stability and installation risk, and the stress envelope and minimum safety factor are used to determine high-risk areas related to structural strength.

[0090] Specifically, in this embodiment, the stress envelope is used to identify critical locations related to structural strength: by extracting the maximum equivalent stress values ​​at each location on the suspended component under all working conditions and at all times, a cloud map of the ultimate stress distribution across the entire field is formed, enabling designers to intuitively locate the critical areas with the highest stress levels in the structure (such as the root of the lifting lug, weld joints, locations of abrupt changes in cross-section, etc.), providing a basis for local reinforcement and structural optimization.

[0091] The lifting point tension envelope is used for sling and lifting point load verification: by extracting the maximum tension value of each sling under all working conditions, it can be directly compared with the rated load capacity of slings, shackles, lifting rings and other lifting tools to determine whether there is an overload risk, and provide a quantitative load basis for the selection of lifting tool specifications, avoiding lifting tool breakage accidents caused by insufficient estimation of lifting point force.

[0092] Attitude deviation envelope is used to assess attitude stability and installation risk: by extracting the maximum angle (including yaw, pitch, and torsion angles) of the suspended component deviating from the ideal attitude throughout the entire lifting process, the attitude stability of the component can be quantitatively evaluated. When the attitude deviation exceeds the preset limit, it means that the component may fail to align with the installation interface due to excessive tilting, or may scrape or collide with surrounding installed structures in a narrow space, thus identifying installation risks in advance.

[0093] The minimum safety factor is used to identify high-risk areas related to structural strength: it directly reflects the safety margin at the weakest point of the structure by calculating the minimum ratio of the allowable stress to the actual stress at each point of the component. When the minimum safety factor is less than 1, it indicates that the actual stress at that location has exceeded the allowable range of the material, posing a risk of yielding or failure. Adjustments to the process parameters for the corresponding operating conditions or structural reinforcement of that area are necessary.

[0094] By applying the above four indicators in a coordinated manner, this invention can conduct a comprehensive safety assessment of the hoisting scheme from three dimensions: structural strength, lifting load, and attitude control, forming a multi-level quantitative risk criterion, which effectively makes up for the shortcomings of traditional methods that rely solely on a single static strength check.

[0095] Furthermore, in some embodiments of the present invention, a wind load condition may also be included. When hoisting operations are carried out at high altitudes or outdoors, a wind load force is applied to the windward side of the hoisted component in the hoisting system simulation model. The formula for calculating the wind load force is as follows:

[0096] in, The wind load is the total resistance force exerted by wind on the windward side of a structural member, expressed in Newtons (N). This refers to air density, expressed in kg / m³. This is the drag coefficient, which is related to the shape of the component (1.1-1.3 for plates and shells, and 0.8-1.0 for cylinders), and is dimensionless. This refers to the area of ​​the component projected onto a plane perpendicular to the wind direction, i.e., the windward area, measured in m². The average wind speed in the hoisting area, measured in m / s or defined by specifications, is used to quantitatively assess the impact of wind load on hoisting attitude deviation and sling stress.

[0097] Furthermore, in some embodiments of the present invention, the method further includes the step of establishing a parameterized hoisting control template: First, in simulation software (Abaqus, ANSYS, or a self-written script), the main control parameters such as maximum lifting acceleration, maximum braking deceleration, maximum uniform speed, braking time, equivalent length of each sling, angle of the cable, equivalent modulus of sling segments, damping coefficient of the sling, stiffness coefficient and damping coefficient of the buffer element are defined as editable variables.

[0098] Secondly, write a parameter template file (such as .txt, .json, or .csv format), in which variable names, default values, allowed ranges, and unit descriptions are defined.

[0099] Finally, a script (such as Python for Abaqus or APDL macro for ANSYS) is used to read the template file, automatically generate the corresponding simulation input file, and automatically adjust the acceleration curve, sling stiffness, buffer contact parameters, time step and solution control parameters according to the parameters; realize the parameterized simulation process of "one-click modification and one-click run", generate multiple sets of parameter combinations in batches through templates and automatically submit the solution.

[0100] Furthermore, in some embodiments of the present invention, the method further includes: intelligent post-processing and automatic risk identification steps, such as automatically extracting the equivalent stress field, suspension point tension, and attitude angle at each moment from the simulation output file, normalizing the time history data into a unified time step format in the simulation software, and calculating the stress gradient change rate, attitude change rate, and sling stress unevenness coefficient using the following formulas:

[0101]

[0102]

[0103] in, The stress gradient change rate, For the rate of attitude change, This is the coefficient for uneven stress distribution in the sling.

[0104] When the above indicators exceed the preset threshold (e.g., the rate of change of stress gradient is greater than the critical value or...), When the value is greater than 1.3), a potential risk is identified at that moment. Secondly, clustering algorithms (such as K-means or DBSCAN) can be used to analyze the high-dimensional feature vectors. Cluster analysis is performed to identify anomalous clusters (i.e., sparsely distributed or abruptly changed samples) and mark them as high-risk points. At the same time, the corresponding working condition number and specific time step are recorded. Then, the identified risk nodes (i.e., working condition number and time step) are associated with the stress cloud map, and color labels (such as red for high risk, yellow for medium risk, and green for safety) are automatically added to the 3D model. Critical moment annotations are automatically inserted into the attitude time history curve to achieve synchronous visualization of stress distribution and time evolution.

[0105] Furthermore, in some embodiments of the present invention, the method further includes database construction and three-dimensional visualization steps: the simulation results of all working conditions are stored in the database, the database fields include working condition type, loading curve, sling parameters, balance beam parameters, maximum stress and attitude deviation, critical moment and position coordinates, and suggested safe acceleration and buffer configuration. The system can automatically generate a three-dimensional dynamic visualization interface of the hoisting path, link and display the stress cloud map and attitude change curve of the hoisted component, and mark the critical moment and critical area on the time axis and three-dimensional model, realizing the structured storage and traceable display of the simulation results of the entire hoisting process, and providing data support for the reuse and standardized design of hoisting schemes for subsequent similar projects.

[0106] In summary, the multi-condition dynamic simulation and safety assessment method for lifting large components of a tokamak according to embodiments of the present invention establishes a dynamic model including the lifted component, balance beam, cable-stayed mechanism, and slings, and defines multiple typical conditions such as lifting acceleration, constant speed, braking deceleration, swinging, and buffer collision. This method can realistically reflect the dynamic response of the entire lifting process, overcoming the shortcomings of traditional static analysis in failing to capture peak inertial loads and attitude changes. Through explicit or transient dynamic time history solving and multi-condition envelope analysis, the method can extract stress envelopes, lifting point tension envelopes, attitude deviation envelopes, and minimum safety factors, achieving limit state assessment and risk identification under multiple superimposed conditions. Finally, it automatically generates a lifting risk identification report, providing quantitative safety assessment basis for the lifting process design of large components of a tokamak, effectively improving the safety margin and reliability of the lifting scheme.

[0107] 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). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0108] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0109] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0110] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0111] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0112] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0113] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0114] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for multi-condition dynamic simulation and safety assessment of hoisting large components of a tokamak, characterized in that, The method includes: A simulation model of the hoisting system is established, which includes a model of the hoisted component, a model of the balance beam and cable-stayed mechanism, and a model of the slings. Define each working condition during the hoisting process, and apply corresponding dynamic displacement or load boundary conditions to the hoisting system simulation model according to each working condition. Each working condition includes hoisting acceleration, constant speed, braking deceleration, swinging, and buffer collision. The simulation model of the hoisting system is solved by time history integration under each working condition using explicit dynamics or transient dynamics methods to obtain the time history data of stress, displacement, attitude and tension at each hoisting point of the hoisted component under each working condition. Envelope analysis is performed on the time history data of stress, displacement, attitude and tension at each lifting point of the suspended component under various working conditions. The stress envelope, tension envelope at each lifting point, attitude deviation envelope and minimum safety factor of the suspended component under various working conditions are extracted to identify risks in each working condition of the lifting process. Based on the risk identification results of each working condition in the hoisting process, a hoisting risk identification report is generated.

2. The method according to claim 1, characterized in that, The establishment of the hoisting system simulation model includes: The suspended component model is established as a flexible body model; A rigid body reference point is set, and the sling model, the balance beam model and the suspended component model are coupled and connected through the rigid body reference point to form a rigid-flexible coupled overall model, so as to realize the synchronous response of rigid body motion and flexible deformation.

3. The method according to claim 1, characterized in that, The relationship between axial force and strain in the sling model is as follows: in, The axial tension of the sling For engineering strain strain rate The equivalent cross-sectional area of ​​the sling Initial length of the sling Initial equivalent elastic modulus Secondary equivalent elastic modulus Equivalent viscous damping coefficient Stage-boundary strain This is the ultimate strain.

4. The method according to claim 1, characterized in that, In the lifting acceleration condition, the constant speed condition, and the braking deceleration condition, the applied dynamic displacement or load boundary conditions are as follows: in, This refers to the vertical displacement of the lifting point or the suspended component. For lifting speed, For maximum lifting acceleration, For maximum braking deceleration, For the maximum uniform speed, To accelerate the end time of the segment, The time at the end of the uniform speed segment. This is the end time of the braking phase. This is a time variable used temporarily during the integration process.

5. The method according to claim 1, characterized in that, In the aforementioned buffer collision condition, the applied dynamic displacement or load boundary conditions are as follows: And the energy absorbed during the buffering process must satisfy: in, To buffer force, For compression amount, For compression rate, The stiffness coefficient of the buffer element. The damping coefficient is... The kinetic energy of the hoisting system at the moment of braking. For safety reasons, The total mass of the hoisted system. The instantaneous velocity of the suspension point at the initial moment of braking.

6. The method according to claim 1, characterized in that, In the aforementioned oscillating condition, the applied dynamic displacement or load boundary conditions are as follows: or in, This refers to the lateral displacement of the lifting point or component. This represents the maximum lateral displacement caused by the initial disturbance or perturbation. The angular frequency of the external excitation. This refers to the lateral displacement of the suspended component or lifting point relative to its equilibrium position. , These are lateral acceleration and velocity, respectively. This represents the ratio of system damping to critical damping. The system's natural angular frequency, External lateral disturbance force, For the equivalent quality of the system.

7. The method according to claim 1, characterized in that, When using the explicit dynamic solution, the time step is... The following conditions must be met: in, For safety reasons, The feature length of the unit. For material wave velocity, The elastic modulus of the material, The density of the material.

8. The method according to claim 1, characterized in that, The risk identification report includes the coordinates of the hazardous node, the time of the hazardous event, the operating condition input information, and the risk level.

9. The method according to claim 1, characterized in that, The method further includes: Multiple sets of different hoisting process parameter combinations are set, and each set of hoisting process parameter combinations is simulated to obtain multiple sets of simulation result samples; Based on the multiple sets of simulation results, a response surface model is established, and the hoisting process parameters are back-optimized according to the response surface model to obtain the optimal combination of hoisting process parameters that meets the safety constraints and attitude accuracy indicators.

10. The method according to claim 1, characterized in that, The tension envelope of the lifting point is used for the load-bearing capacity verification of the sling and the lifting point, the attitude deviation envelope is used to determine the attitude stability and installation risk, and the stress envelope and the minimum safety factor are used to determine the high-risk areas related to structural strength.

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