Bridge BIM model to finite element model conversion method and system

Abstract

The present disclosure provides a bridge BIM model to finite element model conversion method and system, the method comprises the following steps: S1, based on the bridge BIM model, the component number, the three-dimensional geometric information of component and the hanging attribute related to mechanics are extracted, and the section mechanical property is calculated;With component number as primary key, the three-dimensional geometric information, the hanging attribute related to mechanics and the section mechanical property are associated to obtain structured data;S2, through the component conversion algorithm, the structured data is converted to obtain the finite element component;S3, the finite element component is connected, the finite element model is generated, and the load information is added;S4, the convergence of the finite element model is checked. Through the method of the present disclosure, efficient and stable conversion between BIM model and finite element skeleton model can be realized, and the reuse efficiency of BIM model data is improved.

Description

Technical Field

[0001] This disclosure relates to the field of engineering digital technology, and in particular to a method and system for converting a bridge BIM model into a finite element model. Background Technology

[0002] Currently, Building Information Modeling (BIM) software has significant advantages in ease of use, modeling efficiency, and model data management. Meanwhile, Finite Element Analysis (FEA) software is widely used in structural stress analysis in civil engineering. In engineering practice, BIM modeling software focuses on expressing the model's geometric structure and engineering attributes, while finite element models concentrate on structural mechanics analysis and calculation; their focuses differ.

[0003] However, most BIM modeling software currently lacks the ability to directly perform finite element analysis and does not provide an effective interface with mainstream finite element software (such as Midas Civil). Finite element software cannot directly use the native data of BIM models. In other words, when using finite element software to perform structural mechanics analysis calculations, users need to manually recreate the model's geometry and mechanics-related data, which limits the reuse efficiency of BIM model data.

[0004] In engineering modeling applications, especially in scenarios such as bridge engineering, designers urgently need BIM models to be integrated throughout the entire process of structural modeling, stress analysis, and structural optimization. Therefore, how to achieve efficient and stable conversion between BIM models and finite element skeleton models, and expand the functionality of BIM modeling software in the integrated process, has become a key research direction in the current field of BIM modeling software integration and development. Summary of the Invention

[0005] This disclosure provides a method and system for converting a bridge BIM model to a finite element model, which can achieve efficient and stable conversion between BIM models and finite element skeleton models, and improve the reuse efficiency of BIM model data.

[0006] Firstly, this disclosure provides a method for converting a bridge BIM model to a finite element model, including: Step S1: Based on the bridge BIM model, extract the component number, the three-dimensional geometric information of the component, and the mechanically related attachment attributes, and calculate the cross-sectional mechanical properties; using the component number as the primary key, associate the three-dimensional geometric information, the mechanically related attachment attributes, and the cross-sectional mechanical properties to obtain structured data; Step S2: Using a component transformation algorithm, finite element components are obtained based on structured data. Step S3: Connect the finite element components, establish the anchorage connection between the foundation structure and the ground, generate the finite element model, and add load information. Step S4: Perform convergence verification on the finite element model.

[0007] In some embodiments, step S4: performing convergence verification on the finite element model includes verifying the connection integrity and ground anchorage of the bridge finite element model, verifying the continuity of the mechanical properties of the cross sections on the finite element nodes, and verifying the loads applied to the finite element model.

[0008] In some embodiments, the verification of the connection integrity and ground anchorage of the bridge finite element model includes: Based on the connection relationship between finite element elements, a set of reachable nodes is constructed. The set of reachable nodes is compared with the set of all nodes in the finite element model. If the two are consistent, the model connection structure is considered complete and passes the verification. If there are nodes that do not appear in the set of reachable nodes, the nodes are identified as abnormal connection nodes. Check whether the pile foundation is anchored to the ground. If the pile foundation node has a connection with the ground node, the anchoring is deemed effective; if no connection with the ground is detected, the node is marked as an unanchored node.

[0009] In some embodiments, the verification of the continuity of the cross-sectional mechanical properties at the finite element node includes: 1) The mechanical properties of the cross sections corresponding to two adjacent finite element nodes are judged to be continuous when the following conditions are met: a) The outer contours of adjacent cross sections are basically the same; b) The variation range of the moment of inertia of adjacent cross sections is within the first preset tolerance range; c) The variation range of the rotational inertia and shear modulus of adjacent cross sections is within the second preset tolerance range. 2) If the mechanical properties of the entire component section are continuous, then the verification is passed; otherwise, record the node numbers where the mechanical properties of the section change significantly.

[0010] In some embodiments, the load verification applied to the finite element model includes node concentrated load verification and element uniformly distributed load verification.

[0011] In some embodiments, if the bridge finite element model passes all of the above verification items, the finite element model is determined to have passed the convergence verification; if any verification item fails, the finite element model is determined to have failed the convergence verification.

[0012] In some embodiments, in step S2, 1) in the superstructure, substructure and foundation, for a certain component geometric feature type under a certain component type, the optimal component conversion algorithm is selected according to the algorithm fit and computational efficiency, and the optimal component conversion algorithm is used to convert the structured data into finite element components; 2) for all components in the support structure, a unique preset component conversion algorithm is uniformly used to convert the structured data into finite element components.

[0013] In some embodiments, the algorithm fit includes the degree of fit of the cross-section processing method and the minimum spacing of finite element nodes.

[0014] In some embodiments, in step S1, the structured data is in JSON format.

[0015] Secondly, this disclosure provides a system for converting a bridge BIM model to a finite element model, used to perform the aforementioned method for converting a bridge BIM model to a finite element model, characterized in that the system comprises: The structured data generation module is used to extract component numbers, three-dimensional geometric information of components, and mechanically related attachment attributes based on the bridge BIM model, and to calculate the mechanical properties of the cross sections; using the component number as the primary key, it associates the three-dimensional geometric information, mechanically related attachment attributes, and cross section mechanical properties to obtain structured data; The finite element component conversion module is used to convert structured data into finite element components through a component conversion algorithm. The finite element model conversion module is used to connect finite element components, establish anchorage between the foundation structure and the ground, generate a finite element model, and add load information. The convergence verification module is used to verify the convergence of the finite element model.

[0016] The beneficial effects of this disclosure are that, compared with the prior art, this disclosure has the following advantages: 1. This disclosure provides a general framework for converting bridge finite element models, enabling efficient and stable conversion between BIM models and finite element skeleton models, improving the reuse efficiency of BIM model data, and expanding the application of BIM modeling software in finite element stress analysis.

[0017] 2. This disclosed solution starts from BIM model data, can automatically extract key data, and reprocess some data to generate structured data that can be directly called as standardized input data when converting finite element components, thereby improving the reuse efficiency of BIM model data.

[0018] 3. This scheme pre-sets multiple component conversion algorithm templates for different types of components in bridge structures. Taking into account modeling accuracy and algorithm efficiency, the optimal component conversion algorithm is selected through a dynamic comparison mechanism. Thus, while ensuring model accuracy and stability, it achieves synergistic optimization of modeling efficiency and computational performance, obtaining the optimal finite element modeling scheme that simultaneously meets accuracy requirements and high conversion efficiency.

[0019] 4. This disclosed solution constructs a systematic convergence verification process to comprehensively verify key elements such as the connection integrity, anchorage stability, continuity of cross-sectional mechanical parameters, and rationality of load settings of the finite element skeleton model, ensuring that the generated finite element model has good stability and engineering applicability in both structural and mechanical properties, providing a stable model foundation for subsequent structural analysis. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0021] Figure 1 A schematic diagram illustrating a method for converting a bridge BIM model to a finite element model, as provided in this embodiment of the disclosure; Figure 2 This is a schematic diagram of the structural types of various parts of the bridge in the BIM model provided in this embodiment of the disclosure; Figure 3 A schematic diagram of the segmentation method for extracting key points and cross-sectional information from a BIM model according to an embodiment of this disclosure; Figure 4 This is a schematic diagram illustrating the method of obtaining the cross-section of a bridge main beam using a segmented partitioning method and converting it into a finite element component, as provided in this embodiment of the disclosure. Figure 5 This is a schematic diagram illustrating a structured JSON data storage method provided in an embodiment of this disclosure; Figure 6 A schematic diagram of the convergence verification method provided in the embodiments of this disclosure; Figure 7 This is a schematic diagram of a bridge finite element skeleton model provided in an embodiment of the present disclosure; Figure 8 This disclosure provides a schematic diagram of a system for converting a bridge BIM model to a finite element model.

[0022] The accompanying drawings have illustrated specific embodiments of this disclosure, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this disclosure to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0023] The present disclosure will be further described below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solutions of the present disclosure more clearly, and should not be used to limit the scope of protection of the present disclosure.

[0024] The order of steps in this disclosure is merely illustrative. In actual execution, the order may be adjusted as needed, or some steps may be executed in parallel. Unless the execution of a certain step explicitly depends on the result of the previous step, the order between steps does not constitute a limitation of this disclosure.

[0025] Figure 1 This is a flowchart illustrating a method for converting a bridge BIM model to a finite element model according to an embodiment of this disclosure. This method can be executed by a bridge BIM model to finite element model conversion system, which can be implemented in software and / or hardware. It can be integrated as a functional module into existing BIM modeling applications or deployed and run independently.

[0026] like Figure 1 As shown in this embodiment, the method for converting a bridge BIM model to a finite element model may include: Step S1: Based on the bridge BIM model, extract component numbers, 3D geometric information of the components, and mechanically related attachment attributes, and calculate cross-sectional mechanical properties. Using the component number as the primary key, associate the 3D geometric information, mechanically related attachment attributes, and cross-sectional mechanical properties to obtain structured data. Specifically, this includes the following steps: Step S11: Based on the bridge BIM model, extract the component number and the three-dimensional geometric information of the component; Specifically, each component in the BIM model has a unique number (i.e., component ID). A data table is established using this number as the primary key field. When associating the component with its three-dimensional geometric information, mechanically related attachment attributes, cross-sectional mechanical properties, and other data in the future, the association is achieved through this ID number.

[0027] like Figure 2 As shown, the bridge BIM model construction type includes five parts: superstructure, supports, substructure, foundation structure, and auxiliary structures.

[0028] The superstructure includes, for example, the following component types: main beams, end beams, middle beams, and cast-in-place layers. The main beams are usually precast beams or cast-in-place box beams. A bearing is a connecting support structure between the upper and lower structures. It is usually a plate rubber bearing or a pot rubber bearing and includes the following component types: wedge block, brace and pad. The bearing can be omitted when the upper and lower structures are fixed together. The substructure includes two types of structures: piers and abutments. Pier types include column piers, wall piers, and vase-shaped piers, while abutment types include seat plate abutments and U-shaped abutments. Piers include components such as abutment caps and approach slabs, while abutments include components such as pier columns, cap beams, and tie beams. The foundation is the part buried deep underground and connected to the strata, including components such as pile caps and pile foundations; Ancillary structures refer to structures that do not participate in the structural stress but only provide loads, including bridge decks, guardrails, and decorative structures on the bridge surface such as streetlights.

[0029] In one embodiment, extracting the three-dimensional geometric information of the component specifically includes: 1) For supports, the three-dimensional geometric information of the components is obtained by direct extraction method; The direct extraction method uses the secondary development interface provided by BIM software to directly extract the three-dimensional geometric information of the component, including the coverage area of ​​the component (the smallest cuboid that can enclose it), the component's length, width, surface area, volume, and centroid coordinates, which are then stored in association with the component's ID number. This method yields relatively basic three-dimensional geometric information, and in this embodiment, it is only used for support structures.

[0030] Understandably, since the components obtained by the direct extraction method do not need to focus on specific geometric structures, the centroid of the component obtained by the direct extraction method is the key point of the component.

[0031] 2) For the superstructure, substructure, and foundation, the three-dimensional geometric information of the components is obtained by segmentation method; like Figure 3 , Figure 4 As shown, the segmentation method includes: along the length extension direction of the component's three-dimensional geometric information, cutting at intervals perpendicular to the extension direction to obtain multiple cross-sections, extracting the cross-sectional contour shape information, calculating the centroid of the cross-section based on the contour line, and using it as the key point corresponding to the cross-section, recording the key point information and the corresponding cross-sectional contour shape information. The cut cross-sections include at least abrupt cross-sections.

[0032] In this embodiment, a "mutation section" refers to a section where the shapes of the two sides of a cross-section are fundamentally different; for example, the left side of the cross-section is a solid section, while the right side is a hollow section. Such mutation locations are typically written into attribute information during the model creation phase and can be directly read from the BIM model attributes by the 3D model manager for use in component sectioning.

[0033] After identifying the abrupt change in cross-section, the component is segmented with the abrupt change location as the boundary to ensure that the cross-sectional shape and structural parameters within each segment are relatively consistent.

[0034] Specifically, after obtaining multiple cross-sections through sectioning, the contour lines of the cross-sections are extracted using the secondary development interface provided by the BIM software. The centroid of the cross-section is then calculated based on the contour lines and used as the key point corresponding to that cross-section. The key point information is combined with the corresponding section contours into data groups, which are then numbered sequentially according to the order of extension direction of the sectioning position. All data groups are written into a data table and associated with the corresponding component IDs.

[0035] Understandably, the 3D geometric information extracted by the segmentation method includes at least the key point information of the component and the cross-sectional contour shape information corresponding to each key point. The key point information includes the key point number and coordinate data.

[0036] Step S12: Extract the mechanically related connection attributes of each component; Understandably, to construct a finite element model, it's often necessary to extract some geometry-independent but mechanically relevant connection attributes. Mechanically relevant connection attributes include material properties and connection parameters, such as bearing capacity, concrete elastic modulus, and stiffness of the pile foundation-soil connection. This data can be directly extracted from the connection attributes of BIM model components; the types of connection attributes that need to be recorded are usually predefined in a data table.

[0037] Step S13: Calculate the cross-sectional mechanical properties of the component based on its three-dimensional geometric information and mechanically related connection properties.

[0038] In this embodiment, the mechanical properties of the cross section are the cross section mechanical property data required for subsequent stress analysis based on the finite element model (e.g., when calculating the structural stiffness matrix), including parameters such as cross section area, cross section profile shape, cross section moment of inertia, cross section rotational inertia, and cross section shear modulus in the XY direction. Specifically, the cross section profile shape can be obtained from the three-dimensional geometric information of the component extracted in step S11, while other mechanical properties can be calculated based on the cross section profile shape information and material properties.

[0039] In practical implementation, the 3D model manager first filters components containing cross-sections and calculates the mechanical properties of all cross-sections. For simple cross-sections with regular geometry (such as square or circular cross-sections), the mechanical properties are solved using standard calculation formulas defined in industry-standard specifications. For cross-sections with complex geometry (such as octagonal or square cross-sections with holes), conventional methods commonly used in this field, such as the equivalent piecewise method (i.e., calculating mechanical properties by dividing the cross-section into simple cross-sections and then superimposing them) and the numerical integration method (i.e., discretizing the complex cross-section into a set of points and using numerical approximation algorithms such as Monte Carlo integration), can be used for calculation. The above calculation methods are all existing technologies in this field and will not be elaborated further here.

[0040] Finally, the obtained cross-sectional mechanical properties are associated with the key points determined in step S11 and stored in the data table.

[0041] Understandably, the mechanical property data of the cross-sections extracted using the segmentation method cannot be directly parsed from the original BIM model because they are not linked to it. This step effectively completes the cross-sectional mechanical property information of the component on the segment, providing the necessary mechanical property data for subsequent finite element modeling and structural mechanics analysis, thus ensuring the accuracy and reliability of the finite element model.

[0042] Step S14: Using the component number as the primary key, associate the three-dimensional geometric information, mechanically related attachment attributes, and cross-sectional mechanical attributes to obtain structured data.

[0043] Specifically, structured data includes the three-dimensional geometric information, cross-sectional mechanical properties, and mechanically related attachment attributes obtained in the above steps, which are stored in different files in the form of JSON data. For example... Figure 5 As shown, the structured data file includes a 3D geometric information JSON file, a cross-sectional mechanical property information JSON file, and a mechanically related attachment property information JSON file.

[0044] It's worth noting that in existing finite element method (FEM) software, to convert data into a finite element model, users need to manually input the 3D geometric information, cross-sectional mechanical properties, and mechanically related connection attributes of each component. This means re-inputting the geometric and mechanical data of the original model into the FEM software, which then converts it into a finite element model based on the user's input and performs further structural stress analysis. As you can imagine, this method is complex and cannot effectively reuse BIM model data.

[0045] This embodiment starts from BIM model data, can automatically extract key data, and reprocess some data to generate structured data that can be directly called as standardized input data when converting finite element components. This is one of the innovations of this disclosure.

[0046] Step S2: Obtain finite element components based on structured data through a component transformation algorithm.

[0047] The specific implementation method of the component-level component transformation algorithm is as follows: Based on structured data containing cross-sectional mechanical properties, the key point information in the three-dimensional geometric information of the component is extracted, and finite element elements and finite element nodes are generated according to the key point information and the finite element node spacing set by the component transformation algorithm. Corresponding finite element nodes, mechanically related attachment attributes and cross-sectional mechanical properties are added to the finite element elements. The link relationship between finite element elements is established according to the shared nodes, thereby generating finite element components.

[0048] It should be noted that there is a general method for the specific implementation of the component conversion algorithm in structural stress analysis engineering applications, which is an existing technology in this field, and this disclosure does not make any specific limitations on it.

[0049] The component transformation algorithm processes components, that is, it transforms finite element components based on structured data, taking the component level as the unit, during the transformation process.

[0050] In this embodiment, for the support structure, since its structure is relatively simple, it is usually modeled using only a single elastic connection method. That is to say, only one component conversion algorithm is provided for the support structure, which can be directly used for the finite element component conversion of the support structure.

[0051] In specific engineering implementation, for components in the superstructure, substructure, and foundation, the algorithm manager pre-sets component conversion algorithm libraries corresponding to different component types. Each component conversion algorithm library pre-sets multiple component conversion algorithm sub-libraries corresponding to different component geometric structural feature types. For example, the main beam component algorithm library includes a simple-supported precast beam algorithm sub-library, a continuous precast beam algorithm sub-library, and a cast-in-place box girder algorithm sub-library, etc. The pier column component algorithm library includes a single-column vase pier component conversion algorithm sub-library with bifurcations and a multi-column pier component conversion algorithm sub-library with tie beams, etc.

[0052] Specifically, the geometric features of components include, but are not limited to, the shape of their outlines and the distribution of their cross-sectional shapes. Understandably, differences in the main geometric features will lead to different finite element element organization frameworks and node connection methods; therefore, the system needs to match different component transformation algorithms accordingly.

[0053] In each component conversion algorithm sub-library, the algorithm manager pre-defines a component conversion algorithm with a complete variable cross-section modeling processing method for each type of component geometric structure feature. It further includes algorithm variants of this complete variable cross-section modeling processing method in terms of cross-section processing and / or finite element node minimum spacing refinement. In this embodiment, the pre-defined component conversion algorithm with a complete variable cross-section modeling processing method refers to an algorithm that uses the complete variable cross-section modeling processing method during the modeling process, and where the finite element node spacing is a default preset value (for example, for a pier component, the default preset value for the finite element node spacing can be set to 1m).

[0054] It should be noted that in specific engineering implementations, when transforming the finite element node spacing of the algorithm, the node spacing is usually further refined only for complex cross-sectional segments with significant stress changes in the component. Different degrees of refinement result in different algorithm variants. For other segments with relatively uniform stress distribution (such as the main body of the component), further refinement of the node spacing is usually unnecessary (i.e., other segments still use the default preset values). For example, when refining the minimum finite element node spacing of the algorithm for a bifurcated single-column vase-shaped pier, only the bifurcated segment is modeled with a node spacing of 0.5m; other segments still use 1m as the node spacing. Therefore, the minimum finite element node spacing, i.e., the finite element node spacing corresponding to the complex cross-sectional segment with significant stress changes in the component, is used here as a classification index for the algorithm.

[0055] In practical modeling, various component conversion algorithms offer different levels of model fit and computational efficiency. Generally, higher model fit results in a more detailed finite element model, but also increases modeling and subsequent solution computation time, and makes model convergence more difficult. For example, when performing full-condition modeling and simulation analysis on some complex bridge models, a single complete calculation cycle may exceed 5 hours, but the improvement in computational accuracy may not be significant. Therefore, designers typically need to balance model fit and computational efficiency. For instance, while ensuring that the model fit meets engineering requirements, a modeling method with a higher degree of structural simplification can be selected to shorten the overall modeling and simulation time.

[0056] Therefore, in this embodiment, when selecting component conversion algorithms for components in the superstructure, substructure, and foundation, both modeling fit and computational efficiency are comprehensively considered. The optimal component conversion algorithm is determined through dynamic comparison and analysis, thereby ensuring the reliability of modeling while achieving high efficiency in the finite element modeling process.

[0057] In one optional implementation, step S2 is carried out as follows: 1) In the superstructure, substructure and foundation, for a certain component geometric feature type under a certain component type, the optimal component conversion algorithm is selected according to the algorithm fit and computational efficiency. The optimal component conversion algorithm is used to convert the structured data into finite element components; 2) For all components in the support structure, a unique preset component conversion algorithm is uniformly used to convert the structured data into finite element components.

[0058] The following are the specific implementation steps for step S2: Step S21: For components in the superstructure, substructure, and foundation, identify the current component type and component geometric features, and select candidate component conversion algorithms; The alternative component conversion algorithm includes a component conversion algorithm for the complete variable cross-section modeling processing method corresponding to the component geometric feature type under the current component type, and also includes an algorithm variant of the component conversion algorithm for the complete variable cross-section modeling processing method in terms of cross-section processing method and / or finite element node minimum spacing refinement.

[0059] In the specific implementation, for the component to be converted, the algorithm manager first identifies the component type and selects the component conversion algorithm library for that component type from the algorithm library. Then, it analyzes the geometric structural features of the current component, including the outline form, cross-sectional shape distribution features, etc., and selects the component conversion algorithm sub-library that matches the geometric structural features of the current component from the component conversion algorithm library and adds it to the candidate component conversion algorithm library.

[0060] Step S22: Execute the conversion algorithms for each candidate component and monitor the execution efficiency to determine the suitability of the candidate component conversion algorithms. Calculate the score according to the following formula:

[0061] Where α is the final score; t is the calculation time of the candidate component conversion algorithm in seconds; δ is the ranking of the degree of fit between the cross-section processing method and the corresponding algorithm, with the complete variable cross-section modeling processing method ranking as 1, the middle complex cross-section replaced by simple cross-section modeling processing method ranking as 2, and the equal cross-section equivalent replacement modeling processing method ranking as 3. The minimum spacing between finite element nodes in the transformation algorithm for this component is given in meters. Understandably, the scoring method follows the principle of "fit first, computational efficiency second".

[0062] In one embodiment, the step of executing each alternative component conversion algorithm and monitoring execution efficiency includes: the calculation manager executing multiple alternative component conversion algorithms, monitoring and recording the calculation time of each alternative algorithm; In one embodiment, the algorithm fit includes two parameters: the degree of fit of the cross-section processing method and the minimum spacing between finite element nodes.

[0063] The degree of fit of the cross-section processing methods, from high to low, is as follows: complete variable cross-section modeling, modeling with a simple cross-section replacing a complex cross-section in the middle, and modeling with an equivalent replacement of a uniform cross-section. Optionally, the algorithm ranking corresponding to the complete variable cross-section modeling processing method is 1, the algorithm ranking corresponding to the modeling with a simple cross-section replacing a complex cross-section in the middle is 2, and the algorithm ranking corresponding to the modeling with an equivalent replacement of a uniform cross-section is 3.

[0064] Among them, complete variable cross section modeling refers to directly based on the original structural form, retaining the characteristics of its cross section changing along the length of the component, and establishing a variable cross section model that reflects the original structural line shape; Modeling a complex section in the middle by replacing it with a simple section means simplifying the complex section in the middle part while preserving the overall structural characteristics of the component, that is, replacing it with a simple section. In bridge component modeling, since the complex cross-section in the middle is usually located in a region with relatively uniform stress distribution, its details have little impact on the overall stress response. Therefore, a simple cross-section can be reasonably used to replace it locally with an equivalent one, thereby improving the efficiency of modeling while ensuring the accuracy of calculation.

[0065] Equivalent replacement modeling refers to converting a variable cross-section member into a uniform cross-section member model with equivalent mechanical properties (such as stiffness and mass distribution) to simplify the calculation process.

[0066] It should be noted that not all candidate algorithms for the components to be converted include the three cross-section processing methods mentioned above. The above ranking is only used to clarify the order of the compatibility of the three cross-section processing methods and to serve as a reference for judging the degree of algorithm compatibility.

[0067] The minimum spacing between finite element nodes refers to the minimum spacing between finite element nodes, that is, the spacing between finite element nodes corresponding to complex cross-sections with significant stress changes in a component. The smaller the minimum spacing between finite element nodes, the higher the modeling accuracy. In this embodiment, the fit of the component transformation algorithm is jointly determined by the fit of the algorithm's cross-section processing method and the minimum spacing index of finite element nodes. It is understandable that a higher fit of the processing method for the component cross-section and a smaller minimum node spacing indicates a higher algorithm fit.

[0068] Step S23: The algorithm with the highest score is selected as the optimal component conversion algorithm. The processing result of the optimal component conversion algorithm is selected as the current finite element component conversion result. The optimal component conversion algorithm is also used as the optimal component conversion algorithm for subsequent components with the same component type and component geometric feature type as the current component. Specifically, in the subsequent component transformation, if the geometric structure features of a certain component are the same as the component type and geometric structure feature type currently being transformed in this step, then the optimal component transformation algorithm can be directly selected as the component transformation algorithm for the subsequent component.

[0069] Step S24: For all components in the support structure, a unique preset component conversion algorithm is used to convert the structured data into finite element components.

[0070] For the support structure, since its structure is relatively simple, it is usually modeled using only a single elastic connection method. That is to say, for all components in the support structure, there is only one general component conversion algorithm. Therefore, for the support structure, there is no need to perform algorithm comparison in step S2; the preset, unique component conversion algorithm applicable to all support components can be directly called to complete the modeling calculation.

[0071] It should be noted that the auxiliary structures themselves hardly participate in mechanical calculations and are usually only provided as gravity loads. Therefore, the finite element modeling conversion process in this step only applies to the four parts: the superstructure, the substructure, the foundation structure, and the supports. The auxiliary structures are only added to the finite element model as load information.

[0072] Furthermore, in real-world engineering environments, the computation time of different algorithms typically varies, and the computation time t and minimum node spacing also play a role. Furthermore, the sorting δ based on the compatibility of the cross-section processing method is generally a floating-point number or a discrete value with clearly distinguishable values; therefore, identical scores will not occur. This embodiment determines the unique optimal component conversion algorithm by selecting the algorithm with the highest score. If identical scores occur in special cases, it indicates that the two algorithms have comparable performance, and either one can be chosen.

[0073] Step S3: Connect the finite element components, establish the anchorage connection between the foundation structure and the ground, generate the finite element model, and add load information.

[0074] 1) Add link relationships (such as common nodes, elastic links or rigid connections) between finite element components, and establish anchorage connections between pile foundation components and the ground to generate a complete bridge finite element model; This completes the rapid conversion from component-level finite element elements to a bridge finite element skeleton model, such as... Figure 7 As shown.

[0075] 2) Add load information to the finite element model.

[0076] After the finite element skeleton model is built, loads need to be added to the model. In this embodiment, gravity loads, traffic loads, wind loads, and construction loads are added to the model according to standard construction conditions.

[0077] Understandably, the auxiliary structures themselves hardly participate in mechanical calculations and are usually only provided as gravity loads, which are then added to the finite element model as gravity load information.

[0078] Thus far, this embodiment has completed the construction process of the finite element skeleton model. To further ensure that the model has good stability and engineering applicability, this disclosure provides an implementation process for performing convergence verification on the model.

[0079] It should be noted that this step is used to verify the structural rationality and stability of the currently generated bridge finite element skeleton model, and does not involve automatic model repair or improvement. If any abnormal situation that does not meet the convergence requirements is detected during the verification process, or if there is a potential risk of convergence divergence, the message manager module will feed back detailed detection results (including abnormal nodes, abnormal elements, and error messages, etc.) to the user interface to prompt manual intervention and correction.

[0080] Step S4: Perform convergence verification on the finite element model.

[0081] like Figure 6 As shown, the steps for verifying the overall convergence of the transformed finite element model in this embodiment include: verifying the connection integrity and ground anchorage of the bridge finite element model, verifying the continuity of the mechanical properties of the cross sections at the finite element nodes, and verifying the loads applied to the finite element model. The first two steps are for detecting the stability of the finite element model itself, and the last step is for detecting the loads to ensure that the load magnitude meets the requirements of the bridge design specifications.

[0082] Step S41: Verify the integrity of node connections and ground anchorage of the finite element model.

[0083] To ensure the bridge finite element skeleton model possesses good structural connectivity and anchorage stability, this step systematically verifies the integrity of connections between model nodes and the ground anchorage condition, specifically including the following steps: 1) Based on the connection relationship between finite element elements, construct a set of reachable nodes. Compare the set of reachable nodes with the set of all nodes in the finite element model. If they are consistent, the model connection structure is considered complete and passes the verification. If there are nodes that do not appear in the set of reachable nodes, the node is identified as a connection anomaly node. Specifically, when constructing the set of reachable nodes, the set of reachable nodes can be obtained by traversing the model along the element connection path or the elastic connection path based on the connection relationship between finite element elements.

[0084] 2) Check whether the pile foundation is anchored to the ground. If the pile foundation node has a connection with the ground node, the anchoring is deemed effective; if no connection with the ground is detected, mark the node as an unanchored node.

[0085] Specifically, the system traverses the path consisting of the main beam, pier, and pile foundation components in sequence, and checks whether the pile foundation is anchored to the ground. If the pile foundation node has a connection relationship with the ground node, the anchoring is determined to be effective; if no connection relationship with the ground is detected, the node is marked as an unanchored node and its abnormal node number is recorded.

[0086] Step S42, verify the continuity of mechanical properties of the joint sections within the component; This step is used to check the consistency of the mechanical properties of the corresponding sections at each node in the finite element component, ensuring the continuity of the section mechanical properties within the component range. It includes the following steps: 1) The mechanical properties of the cross sections corresponding to two adjacent finite element nodes are judged to be continuous. When the following conditions are met at the same time, the mechanical properties of the cross section are determined to be continuous: a) The outer contours of the adjacent cross sections are basically the same; b) The variation range of the moment of inertia of the adjacent cross sections is within the first preset tolerance range (e.g., 10%); c) The variation range of the rotational inertia and shear modulus of the adjacent cross sections is within the second preset tolerance range (e.g., 5%).

[0087] 2) If the mechanical properties of the entire component section are continuous, then the verification is passed; otherwise, record the node numbers where the mechanical properties of the section change significantly.

[0088] Step S43, load verification of the finite element model, including verification of concentrated loads at nodes and uniformly distributed loads on elements.

[0089] This step verifies the concentrated load at nodes and the uniformly distributed load of elements for the gravity load, traffic load, wind load, and construction load added in step S3, to ensure that the load strength and distribution meet the preset structural safety requirements.

[0090] The node concentrated load verification includes: traversing the finite element nodes, summarizing the concentrated loads applied to each node in each direction, and determining whether they are within the set limit range. If yes, the verification is passed; if no, the node is marked as a load abnormality node.

[0091] In practical implementation, all nodes in the finite element model are traversed, and the concentrated load components applied to each node in each direction (X, Y, Z axes) are read. Vector decomposition is performed, and the loads are accumulated in each direction (X, Y, Z axes). It is then determined whether the following limit conditions are met: a) In the X and Y axis directions, the total concentrated load does not exceed the first limit (e.g., 10). 2 (a) In the Z-axis direction (gravity direction), the total concentrated load does not exceed the second limit (e.g., 10 kN); (b) In the Z-axis direction (gravity direction), the total concentrated load does not exceed the second limit (e.g., 10 kN). 3 (kN). If a node meets the above limit conditions in all directions, the concentrated load on that node is deemed to have passed the verification; otherwise, the node number and the direction of exceeding the limit are recorded. In specific engineering implementation, the first limit is less than the second limit.

[0092] The uniformly distributed load verification of the element includes: traversing the finite element elements, summarizing the uniformly distributed loads applied in each direction on each element, and verifying whether they meet the preset limits. If yes, the verification is passed; if no, the element is marked as an abnormal load element.

[0093] In practice, each finite element element is traversed, and the uniformly distributed load components applied in each direction (X, Y, Z axes) on that element are read. Vector decomposition is performed, and the loads are accumulated in each direction (X, Y, Z axes). It is then determined whether the following limit conditions are met: a) In the X and Y axis directions, the total uniformly distributed load does not exceed the third limit (e.g., 10). 2 (a) The total uniformly distributed load in the Z-axis direction (gravity direction) does not exceed the fourth limit (e.g., 10 kN / m); (b) In the Z-axis direction (gravity direction), the total uniformly distributed load does not exceed the fourth limit (e.g., 10 kN / m). 3 (kN / m). If a node meets the above limit conditions in all directions, the concentrated load on that node is deemed to have passed the verification; otherwise, the node number and the direction of exceeding the limit are recorded. In specific engineering implementation, the third limit is less than the fourth limit.

[0094] Further optionally, step S43, finite element model load verification, further includes: load continuity verification.

[0095] Load continuity verification includes checking the load differences between adjacent nodes or units within a component. If the difference exceeds a preset ratio, it is recorded as a sudden change node or unit. If there are no sudden change nodes or units, the verification is deemed to have passed.

[0096] Specifically, for adjacent nodes within a component, if the difference in concentrated loads in the same direction exceeds a preset proportion (e.g., 10%), it is marked as a concentrated load abrupt change; for adjacent elements within a component, if the difference in uniformly distributed loads in the same direction exceeds a preset proportion (e.g., 10%), it is marked as a uniformly distributed load discontinuity. Record the node numbers or element numbers of all abrupt changes. If no abrupt changes occur in any node or element, the verification is considered successful.

[0097] It should be noted that this continuity check result serves as supplementary information and does not affect whether the load convergence check passes or not.

[0098] Step S44: If the bridge finite element model passes all the above verification items, the finite element model is determined to have passed the convergence verification. If any verification item fails, the finite element model is determined to have failed the convergence verification.

[0099] In this embodiment, if all the above verification items pass, the finite element model is deemed to have passed the convergence verification, and the finite element model is recorded. If any verification item fails, the finite element model is deemed to have failed the convergence verification, and the abnormal nodes, abnormal elements, and their error information generated during the verification process are fed back to the user.

[0100] In practice, when the convergence check fails, the message manager collects abnormal nodes, abnormal elements, and their error information, and displays these information in a pop-up window on the user interface. Based on the feedback, users can quickly locate and troubleshoot potential problems in the conversion process and modify the erroneous data in the BIM model accordingly, so that the finite element model conversion program can be rerun.

[0101] It should be noted that the model constructed in this embodiment is a general finite element model, which is a general format data of finite element software. If it is necessary to import it into a specific finite element software, further format fine-tuning can be performed to generate a data format text for that specific finite element software, such as MCT files for Midas software, TCL files for OpenSEES, and CDB files for ANSYS.

[0102] like Figure 8 As shown, the second embodiment of this disclosure proposes a system 100 for converting a bridge BIM model to a finite element model, used to execute the bridge BIM model to finite element model conversion method as described in the above embodiments. The system includes: The structured data generation module 101 is used to extract component numbers, three-dimensional geometric information of components, and mechanically related attachment attributes based on the bridge BIM model, and to calculate the mechanical properties of the cross sections; using the component number as the primary key, it associates the three-dimensional geometric information, mechanically related attachment attributes, and cross section mechanical properties to obtain structured data; Finite element component conversion module 102 is used to obtain finite element components based on structured data through component conversion algorithm; The finite element model conversion module 103 is used to connect finite element components, establish anchorage between the foundation structure and the ground, generate a finite element model, and add load information; The convergence verification module 104 is used to perform convergence verification on the finite element model.

[0103] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0104] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0105] It should be understood that the above embodiments are only used to illustrate the technical solutions of this disclosure, and not to limit them; although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure.

Claims

1. A method for converting a bridge BIM model to a finite element model, characterized in that, Includes the following steps: S1, based on the bridge BIM model, extract the component number, the three-dimensional geometric information of the component and the mechanical connection attributes, and calculate the mechanical properties of the section; Using the component number as the primary key, and associating it with three-dimensional geometric information, mechanically related attachment attributes, and cross-sectional mechanical properties, structured data is obtained; S2, through a component transformation algorithm, finite element components are obtained based on structured data transformation; S3 connects the finite element components, establishes the anchorage connection between the foundation structure and the ground, generates the finite element model, and adds load information. S4, perform convergence verification on the finite element model; Step S4 involves performing convergence verification on the finite element model, including verifying the connection integrity and ground anchorage of the bridge finite element model, verifying the continuity of the mechanical properties of the cross sections at the finite element nodes, and verifying the loads applied to the finite element model. Step S2, which involves obtaining finite element components based on structured data using a component conversion algorithm, includes: Step S21: For the components in the superstructure, substructure and foundation, identify the current component type and component geometric features, and select candidate component conversion algorithms; Step S22: Execute the conversion algorithms for each candidate component and monitor the execution efficiency to determine the suitability of the candidate component conversion algorithms. Calculate the score according to the following formula: Where α is the final score; t is the calculation time of the candidate component conversion algorithm in seconds; δ is the ranking of the degree of fit between the cross-section processing method and the corresponding algorithm, with the complete variable cross-section modeling processing method ranking as 1, the middle complex cross-section replaced by simple cross-section modeling processing method ranking as 2, and the equal cross-section equivalent replacement modeling processing method ranking as 3. The minimum spacing between finite element nodes in the transformation algorithm for this component is given in meters. Step S23: The algorithm with the highest score is selected as the optimal component conversion algorithm. The processing result of the optimal component conversion algorithm is selected as the current finite element component conversion result. The optimal component conversion algorithm is also used as the optimal component conversion algorithm for subsequent components with the same component type and component geometric feature type as the current component. Step S24: For all components in the support structure, a unique preset component conversion algorithm is used to convert the structured data into finite element components.

2. The method for converting a bridge BIM model to a finite element model according to claim 1, characterized in that, The verification of the connection integrity and ground anchorage of the bridge finite element model includes: Based on the connection relationship between finite element elements, a set of reachable nodes is constructed. The set of reachable nodes is compared with the set of all nodes in the finite element model. If the two are consistent, the model connection structure is considered complete and passes the verification. If there are nodes that do not appear in the set of reachable nodes, the nodes are identified as abnormal connection nodes. Check whether the pile foundation is anchored to the ground. If the pile foundation node has a connection with the ground node, the anchoring is deemed effective; if no connection with the ground is detected, the node is marked as an unanchored node.

3. The method for converting a bridge BIM model to a finite element model according to claim 1, characterized in that, The continuity verification of the cross-sectional mechanical properties at finite element nodes includes: 1) The mechanical properties of the cross sections corresponding to two adjacent finite element nodes are judged to be continuous. When the following conditions are met at the same time, the mechanical properties of the cross sections are judged to be continuous: a) The outer contour shape of the adjacent cross sections is basically the same; b) The variation range of the moment of inertia of the adjacent cross sections is within the first preset tolerance range; c) The variation range of the rotational inertia and shear modulus of the adjacent cross sections is within the second preset tolerance range. 2) If the mechanical properties of the entire component section are continuous, then the verification is passed; otherwise, record the node numbers where the mechanical properties of the section change significantly.

4. The method for converting a bridge BIM model to a finite element model according to claim 1, characterized in that, The load verification applied to the finite element model includes node concentrated load verification and element uniformly distributed load verification.

5. The method for converting a bridge BIM model to a finite element model according to claim 1, characterized in that, If the bridge finite element model passes all the above verification items, it is determined that the finite element model has passed the convergence verification. If any verification item fails, it is determined that the finite element model has failed the convergence verification.

6. The method for converting a bridge BIM model to a finite element model according to claim 1, characterized in that, The algorithm fit includes the degree of fit of the cross-section processing method and the minimum spacing of finite element nodes.

7. The method for converting a bridge BIM model to a finite element model according to claim 1, characterized in that, In step S1, the structured data is in JSON format.

8. A system for converting a bridge BIM model to a finite element model, used to perform the method for converting a bridge BIM model to a finite element model as described in any one of claims 1-7, characterized in that, The system includes: The structured data generation module is used to extract component numbers, three-dimensional geometric information of components, and mechanically related attachment attributes based on the bridge BIM model, and to calculate the mechanical properties of the cross sections; using the component number as the primary key, it associates the three-dimensional geometric information, mechanically related attachment attributes, and cross section mechanical properties to obtain structured data; The finite element component conversion module is used to convert structured data into finite element components through a component conversion algorithm. The finite element model conversion module is used to connect finite element components, establish anchorage between the foundation structure and the ground, generate a finite element model, and add load information. The convergence verification module is used to verify the convergence of the finite element model.

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