Strain gauge layout method and train
By establishing a finite element model and dividing it into weld and base material elements in the vehicle body structure test, calculating the safety factor and identifying dangerous elements, the problems of accuracy and efficiency of strain gauge layout were solved, and precise strain gauge layout and improved data reliability were achieved.
Patent Information
- Application Number
- CN202511159294.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-19
- Publication Date
- 2025-11-25
AI Technical Summary
In vehicle body structure testing, existing technologies struggle to efficiently and accurately place strain gauges within a limited space, resulting in low data accuracy, severe signal interference, and a lack of systematic optimization methods, failing to meet the demands of modern refined vehicle body structure evaluation.
By establishing a finite element model, dividing the weld elements and base material elements, calculating the safety factor and identifying the dangerous elements, the layout of strain gauges is determined based on these results. By combining multi-condition simulation results and three-dimensional visualization technology, accurate safety factor calculation and automated strain gauge layout are achieved.
It improves the accuracy of strain gauge layout and test efficiency, avoids the subjectivity and omissions in manual interpretation, and significantly enhances the reliability of data and the pertinence of tests.
Smart Images
Figure CN121009745A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the technical field of finite element modeling, stress analysis and testing, and more particularly, to a strain gauge layout method and a train. BACKGROUND
[0002] In the field of related vehicle body testing, due to the complex structure and limited space of the vehicle body, the test personnel must balance between the number of test points and data integrity. Although high-density patching can improve data accuracy, it will lead to complex wiring and intensified signal interference, and is difficult to implement in a small space. The related test point layout mainly relies on the experience of engineers, and lacks a systematic optimization method, which can easily cause key areas to be missed or non-critical areas to be redundant. Such experience-oriented testing scheme is difficult to meet the needs of modern vehicle structure fine evaluation, and it is urgent to develop intelligent patching technology based on numerical simulation and optimization theory to improve testing efficiency and data reliability. SUMMARY
[0003] Therefore, the present disclosure provides a strain gauge layout method and a train.
[0004] One aspect of the present disclosure provides a strain gauge layout method, comprising: obtaining a finite element model file created based on a measured object, the finite element model file comprising shell element information, the shell element information representing information of a plurality of shell elements obtained by meshing a finite element model of the measured object, the plurality of shell elements being divided into weld element and base material element; calculating a weld safety factor of the weld element according to a weld allowable stress value and a weld Mises stress value of the weld element; calculating a base material safety factor of the base material element according to a base material allowable stress value and a base material Mises stress value of the base material element; determining a dangerous element in the plurality of shell elements according to the weld safety factor and the base material safety factor; and determining a layout position of a strain gauge in the measured object according to a position of the dangerous element in the finite element model.
[0005] Another aspect of the present disclosure provides a train, wherein a strain gauge is arranged in the train, and the layout method of the strain gauge is determined based on the strain gauge layout method of the present disclosure.
[0006] Based on the technical solution of the present disclosure, by independently calculating the safety factors of the weld element and the base material element and evaluating whether they belong to the dangerous element, the difference in mechanical properties between the welded area and the non-welded area can be effectively considered, and the accuracy of the determination result can be improved. In addition, by combining the allowable stress value and the Mises stress value of each shell element to calculate the safety factor, the traditional reliance on manual experience can be broken through, accurate safety factor calculation and automatic identification of dangerous elements in the welded / non-welded area can be realized, and the problems of low efficiency, strong subjectivity and easy to miss evaluation of manual interpretation can be solved. BRIEF DESCRIPTION OF DRAWINGS
[0007] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:
[0008] Figure 1 A flowchart illustrating a strain gauge layout method according to an embodiment of the present disclosure is shown schematically.
[0009] Figure 2 A schematic diagram of a finite element model of a train according to an embodiment of the present disclosure is shown.
[0010] Figure 3 This illustration schematically shows a hierarchical naming scheme for groups (parts) according to an embodiment of the present disclosure;
[0011] Figure 4 The diagram schematically illustrates a Mises stress cloud plot drawn for a train based on envelope conditions according to an embodiment of the present disclosure;
[0012] Figure 5 A schematic diagram illustrating a shell unit with the positive direction of the Z-axis as the Z1 plane according to an embodiment of the present disclosure;
[0013] Figure 6 A schematic diagram illustrating a dangerous area according to an embodiment of the present disclosure is shown.
[0014] Figure 7 This schematically illustrates the overall flowchart of a train hazard area identification and strain gauge layout optimization method based on finite element simulation according to an embodiment of the present disclosure;
[0015] Figure 8 A block diagram of a strain gauge layout apparatus according to an embodiment of the present disclosure is shown schematically;
[0016] Figure 9 A block diagram of an electronic device suitable for implementing a strain gauge layout method according to an embodiment of the present disclosure is shown schematically. Detailed Implementation
[0017] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.
[0018] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.
[0019] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.
[0020] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).
[0021] In the simulation analysis of vehicle body structure, safety assessments under more than 20 load conditions need to be completed. Because the vehicle body contains numerous parts, and the mechanical properties of welded and non-welded areas differ significantly, previous test layouts relied mainly on manual interpretation and engineering experience, lacking data-driven decision support.
[0022] Figure 1 A flowchart illustrating a strain gauge layout method according to an embodiment of the present disclosure is shown schematically.
[0023] like Figure 1 As shown, the method includes operations S110~S150.
[0024] In operation S110, a finite element model file created based on the object under test is obtained. The finite element model file includes shell element information. The shell element information represents the information of multiple shell elements obtained by meshing the finite element model of the object under test. The multiple shell elements are divided into weld elements and base material elements.
[0025] According to embodiments of this disclosure, by extracting the mid-surface of, for example, a vehicle body structure, creating different groups based on different parts and assigning them corresponding names, and meshing with shell elements of a preset thickness (e.g., 20 mm), performing mesh-shared node processing at the connection points, and / or creating corresponding analysis conditions according to relevant standards, a finite element model for the vehicle body can be obtained, such as... Figure 2 As shown.
[0026] Figure 2 A schematic diagram of a finite element model of a train according to an embodiment of the present disclosure is shown.
[0027] According to embodiments of this disclosure, the completed finite element model can be stored as a finite element model file. The finite element model file can be a text file, which may include at least one of the following information: shell element information, node identifiers, part name, material information, simulation condition information, etc., and is not limited to these. The shell element information may include the shell element identifier, actual material, actual thickness, etc., and is not limited to these. Nodes may represent the mesh vertices of the shell elements, and node identifiers may represent the identifiers of the mesh vertices. Material information may represent the material information used in the part. Simulation condition information may include the constraints and loads corresponding to the simulation conditions, and is not limited to these.
[0028] According to embodiments of this disclosure, shell units can be divided into weld seam units and base material units based on whether their location is within a welding area used for welding different parts. Weld seam units characterize shell units located in the welding area, while all other shell units are referred to as base material units.
[0029] According to embodiments of this disclosure, to facilitate subsequent retrieval, when initializing global variables, a query command can be invoked through the program to automatically view all shell elements, nodes, and other related information, and establish a corresponding dictionary to store the information. For example, a dictionary named dict_Weding_Elem_id can be established to store the shell element identifier (hereinafter referred to as id) of the weld element. For example, for the weld element determined above, its shell element id can be stored in the dict_Weding_Elem_id dictionary. Thus, by determining whether a shell element id exists in the dict_Weding_Elem_id dictionary, it can be intuitively determined whether a shell element belongs to a weld element or a base material element.
[0030] In operation S120, the weld safety factor of the weld unit is calculated based on the allowable stress value and the Mises stress value of the weld unit.
[0031] In operation S130, the safety factor of the base material element is calculated based on the allowable stress value and the Mises stress value of the base material element.
[0032] According to the embodiments of this disclosure, all shell units are traversed. If a certain shell unit ID already exists in the dict_Weding_Elem_id dictionary, then the security factor of that shell unit can be calculated by formula (1).
[0033] Weld safety factor = Allowable stress value of weld / Mises stress value of weld (1).
[0034] If a certain shell cell ID does not exist in the dict_Weding_Elem_id dictionary, then the security factor of the shell cell can be calculated by formula (2).
[0035] Safety factor of base material = Allowable stress value of base material / Mises stress value of base material (2).
[0036] In operation S140, the hazardous elements among multiple shell elements are determined based on the weld safety factor and the base material safety factor.
[0037] According to embodiments of this disclosure, the same or different safety factor thresholds can be set for weld seam units and base material units according to actual business needs, and weld seam units and / or base material units with smaller safety factors can be identified as dangerous units based on the corresponding safety factor thresholds.
[0038] According to embodiments of this disclosure, the hazardous element may further include a shell element determined according to a preset region.
[0039] According to embodiments of this disclosure, the preset area can characterize an area determined based on business needs, for example, it may include... Figure 2 The areas where door corners 201 and window corners 202 are located in the finite element model 200 shown are not limited to these areas.
[0040] According to embodiments of this disclosure, when initializing global variables, a `danger_elem` dictionary can also be created to store the dangerous unit IDs of dangerous units. For example, for dangerous units determined based on the above method, their dangerous unit IDs can be stored in the `danger_elem` dictionary for later use.
[0041] In operation S150, the layout of strain gauges in the measured object is determined based on the location of the hazardous element in the finite element model.
[0042] According to embodiments of this disclosure, based on the location of the hazardous element in the finite element model, the area to be laid out in the finite element model where strain gauges need to be placed can be determined. Thus, by mapping the area to be laid out in the finite element model to the corresponding area of the object under test, the area to be laid out in the object under test can be determined, so as to lay out strain gauges in the object under test.
[0043] It should be noted that the area to be deployed, determined based on the hazardous unit, may be large or small. For example, if the area to be deployed is smaller than a first area threshold, only one strain gauge may be deployed in that area. If the area to be deployed is larger than a second area threshold, multiple strain gauges may be deployed in that area, depending on its specific size. Furthermore, if the area to be deployed is a region such as a gap where it is inconvenient to deploy strain gauges, the strain gauges may be deployed in adjacent areas of that area; this is not a limitation.
[0044] Through the embodiments of this disclosure, by independently calculating the safety factor and assessing whether a weld element or base material element is a hazardous element, the difference in mechanical properties between welded and non-welded areas can be effectively considered, improving the accuracy of the judgment results. Furthermore, by combining the allowable stress value and Mises stress value of each shell element to calculate the safety factor, it is possible to overcome the reliance on traditional manual experience, achieving accurate calculation of the safety factor for welded / non-welded areas and automatic identification of hazardous elements, thus solving problems such as low efficiency, strong subjectivity, and easy omissions in manual judgment.
[0045] The following describes specific embodiments. Figure 1 The method shown will be explained in further detail.
[0046] According to embodiments of this disclosure, the part name in the finite element model file may include a profile field characterizing the profile to which the part belongs and a material field characterizing the material used by the part. During the execution of the above operation S110, weld elements can be determined using the following method: based on node identifiers, multiple related shell elements with node identifiers are determined, and the part name of the part to which each related shell element belongs is obtained, resulting in multiple part names. In response to detecting that the profile field or material field in the multiple part names is different, the multiple related shell elements are determined as weld elements.
[0047] According to embodiments of this disclosure, the naming of groups (parts) follows certain rules. First, they are grouped according to categories: categories are level 1, components are level 2, profiles are level 3, and groups (parts) are level 4, such as... Figure 3 As shown.
[0048] Figure 3 A schematic diagram illustrating hierarchical naming of groups (parts) according to an embodiment of the present disclosure is shown.
[0049] like Figure 3As shown, box 301 represents category-level naming, box 302 represents component-level naming, box 303 represents profile-level naming, and box 304 represents group (part)-level naming. Each name in box 304 can correspond to a part name. Taking the part name SFM117TC1_A701_Floor1_T4.0_E6005-EHP_Re215 as an example, Floor1 can represent the profile field, and E6005-EHP can represent the material field.
[0050] According to embodiments of this disclosure, when initializing global variables, an Elem_Node_info dictionary can be established by querying the finite element model file to store the mapping relationship from shell element ID to node ID and part name, thereby obtaining the shell element-node mapping relationship. Based on this, a node-shell element reverse index can be constructed, including: supplementing the information from node ID to related shell elements according to the Elem_Node_info dictionary, and traversing the Elem_Node_info dictionary. In a loop, based on multiple mapping relationships from shell element ID to node ID, multiple mapping relationships from node ID to shell element ID are established to improve the Node_Elem_info dictionary, realizing bidirectional data association between shell elements and nodes, and improving retrieval efficiency. Specifically, the established Node_Elem_info dictionary can, for example, store node ID, the ID of its own shell element 1, the ID of its own part name 1, the ID of its own shell element 2, the ID of its own part name 2, ..., the ID of its own shell element n, and the ID of its own part name n.
[0051] In determining weld elements by identifying the welding area, the `Node_Elem_info` dictionary is traversed to check if the profile or material field of the part name corresponding to the relevant shell element of the node is inconsistent. If inconsistent, these relevant shell elements can be determined to be weld elements, and their shell element IDs can be stored in the `dict_Weding_Elem_id` dictionary. Based on this method, multiple shell elements in the finite element model can be divided into weld elements and base material elements.
[0052] Through the above embodiments of this disclosure, weld seam units can be reasonably divided, and the mechanical properties of welded and non-welded areas can be accurately distinguished, thereby achieving a refined assessment of the structural safety factor and significantly improving the accuracy and engineering applicability of the calculation results.
[0053] According to embodiments of this disclosure, the finite element model file may include a material property file. The material property file may include allowable stress parameters for weld elements and base metal elements under different materials and thicknesses. Shell element information may include the actual material and actual thickness of the shell elements. Before performing the aforementioned operations S120 and S130, the allowable stress values for the weld and base metal can be determined first based on the aforementioned information. Specifically, the method may include: parsing the material property file to obtain the allowable stress value for the weld based on the actual material and actual thickness of the weld element; and parsing the material property file to obtain the allowable stress value for the base metal based on the actual material and actual thickness of the base metal element.
[0054] For example, when the actual material and actual thickness of the weld element / base material element are directly recorded in the material property file, and the corresponding allowable stress parameters are also directly recorded, parsing the material property file may include: based on the actual material and actual thickness of the weld element / base material element, directly reading the allowable stress parameters corresponding to the weld element / base material element when using the corresponding actual material and actual thickness from the material property file, and using them as the allowable stress value of the weld / base material.
[0055] For example, when the actual material and thickness of the weld element / base material element are not directly recorded in the material property file (i.e., the material property file only directly records the allowable stress parameters corresponding to other materials and / or thicknesses different from the actual material), parsing the material property file can include: determining the target material closest to the actual material among other materials based on material similarity characteristics; determining the target thickness closest to the actual thickness among other thicknesses; reading the target allowable stress parameters corresponding to the weld element / base material element when using the corresponding target material and target thickness from the material property file, and calculating the weld allowable stress value / base material allowable stress value using a preset formula. The preset formula can be determined by constructing a function based on the similarity offset between the actual material and the target material, the thickness offset between the actual thickness and the target thickness, and the target allowable stress parameters.
[0056] Through the above embodiments of this disclosure, the allowable stress values of welds and base metals under various materials and thicknesses can be effectively obtained, which is beneficial for the subsequent calculation of the safety factors of weld units and base metal units.
[0057] According to embodiments of this disclosure, the finite element model file may include multiple simulation condition information, which includes constraints and loads configured for the shell element in the simulation conditions. Before performing the aforementioned operations S120 and S130, the weld Mises stress value and the base material Mises stress value may be calculated based on the multiple simulation condition information. Specifically, the method may include: calculating at least one simulation result information for the shell element based on the simulation condition information of the shell element. The simulation result information includes stress parameter information exhibited by the shell element under simulation conditions with constraints and loads applied to it, and the stress parameter information includes Mises stress values. Based on at least one simulation result information, determining the envelope condition information of the shell element. The envelope condition information includes the target Mises stress value, which is the largest among at least one Mises stress value from the at least one simulation result information. Based on the target Mises stress value, determining the Mises stress value of the shell element to obtain the weld Mises stress value and the base material Mises stress value.
[0058] According to embodiments of this disclosure, constraints can, for example, characterize fixing one end of the object under test. Based on these constraints, a specific implementation of the simulation condition can be constructed by applying a preset load to the other end.
[0059] According to embodiments of this disclosure, by exporting corresponding finite element model (FEM) files based on the categories of working conditions from the established finite element models, and performing calculations in conjunction with the simulation working condition information contained therein, simulation result files of type H3D (Hyper3D Result) can be generated. The simulation result files can include the stress tensors exhibited by the shell elements under various simulation working conditions. The stress tensors are then calculated using post-processing software to obtain simulation result information. The simulation result information can include the mapping relationship between the shell element, the simulation working condition ID, and the stress parameter information, representing the stress parameter information exhibited by the shell element when a simulation working condition with a specific simulation working condition ID is applied to it. The stress parameter information can include Mises stress values, three principal stress values consisting of the maximum principal stress value, the intermediate principal stress value, and the minimum principal stress value, and may also include stress tensors, but is not limited to these.
[0060] According to embodiments of this disclosure, based on a simulation condition information, a corresponding simulation result information can be calculated. By loading an FEM file and multiple H3D simulation result files, at least one simulation result information for each shell element can be calculated, and a list of simulation condition IDs can be obtained to determine the mapping relationship between the recorded simulation condition IDs and simulation condition names.
[0061] According to embodiments of this disclosure, when at least one simulation result information is obtained, an envelope condition information can be generated based on the at least one simulation result information using an envelope function, and the envelope condition ID of the envelope condition can be returned. The envelope condition information may include only the target Myses stress value, which is the largest among at least one Myses stress value from at least one simulation result information, and the simulation condition name of the simulation condition to which the target Myses stress value belongs; the target maximum principal stress value, which has the largest absolute value among at least one maximum principal stress value from at least one simulation result information, and the simulation condition name of the simulation condition to which the target maximum principal stress value belongs; and the target minimum principal stress value, which has the largest absolute value among at least one minimum principal stress value from at least one simulation result information, and the simulation condition name of the simulation condition to which the target minimum principal stress value belongs.
[0062] According to embodiments of this disclosure, when multiple H3D simulation result files are obtained, these multiple H3D simulation result files can be merged in post-processing software, and envelope conditions can be generated from the simulation conditions contained in the multiple H3D results using the envelope function to obtain the aforementioned envelope condition information and return the envelope condition ID. This disclosure does not limit the specific implementation method for creating envelope conditions.
[0063] According to embodiments of this disclosure, by switching the analysis scene to the aforementioned envelope condition, based on the simulation condition name to which the target Myses stress value belongs in the envelope condition information, and combined with the previously obtained list of simulation condition IDs, the simulation condition ID to which the target Myses stress value belongs in the envelope condition information can be determined first. Therefore, the current condition of each shell element can be set according to the simulation condition ID of each shell element determined in the aforementioned manner, thus determining the current settings for the finite element model. Then, using finite element post-processing software, a Myses stress cloud diagram of the finite element model can be drawn based on the current settings, such as... Figure 4 As shown.
[0064] Figure 4 The illustration schematically shows a Mises stress cloud diagram plotted for a train based on envelope conditions according to an embodiment of the present disclosure.
[0065] like Figure 4 As shown, by traversing each shell element in the Mises stress cloud map 400, the Mises stress value of each shell element can be determined. Based on this, combined with the dict_Weding_Elem_id dictionary, the weld Mises stress value of the weld element and the base material Mises stress value of the base material element can be further obtained. Combined with the previously obtained weld allowable stress parameters and base material allowable stress parameters, this supports the calculations of operations S120 and S130.
[0066] Through the above embodiments of this disclosure, it is possible to comprehensively analyze the simulation results of multiple working conditions and obtain the most valuable Mises stress value, which is beneficial for accurately calculating the safety factor of the welded area and the non-welded area and realizing the automatic identification of dangerous units.
[0067] According to embodiments of this disclosure, when the weld safety factor and the base material safety factor are calculated based on the aforementioned information, the above operation S140 may include: in response to determining that the weld safety factor meets a first preset condition, identifying the weld element as a dangerous element; and in response to determining that the base material safety factor meets a second preset condition, identifying the base material element as a dangerous element.
[0068] According to embodiments of this disclosure, the first preset condition and the second preset condition may differ depending on actual business needs. For example, the first preset condition may include: the weld safety factor is less than a first threshold. The second preset condition may include: the base material safety factor is less than a second threshold. Both the first threshold and the second threshold can be determined according to actual business needs. The first threshold may be less than the second threshold.
[0069] It should be noted that the first and second preset conditions mentioned above are merely exemplary embodiments. In actual implementation, they may not be limited to these and may be expressed as other conditions, which are not limited here.
[0070] According to embodiments of this disclosure, after identifying the hazardous element based on the aforementioned method, the layout orientation of strain gauges located in the region of the hazardous element can be further determined by combining envelope condition information. Specifically, the method may include: calculating the principal stress direction of the hazardous element based on the envelope condition information; and determining the layout orientation of strain gauges located in the region of the hazardous element based on the principal stress direction.
[0071] According to embodiments of this disclosure, the principal stress directions can be obtained by combining the stress tensor in the simulation result file of the hazardous element with calculations from finite element post-processing software. Alternatively, stress parameter information related to the principal stress values in the envelope condition information can be used to calculate the principal stress directions. For example, the principal stress directions can be calculated based on the maximum principal stress value, the intermediate principal stress value, and the minimum principal stress value. No limitation is made herein.
[0072] It should be noted that, in order to ensure the effectiveness of the strain gauge layout in the corresponding area without calculating the principal stress direction, multi-axis strain gauge arrangement or strain rosette can be used for layout.
[0073] According to embodiments of this disclosure, calculating the principal stress direction of a hazardous element based on its envelope condition information may specifically include: obtaining a target simulation condition identifier for the target simulation condition to which the target principal stress value belongs, based on the target principal stress value with the larger absolute value between the target maximum and target minimum principal stress values of the hazardous element; determining the target stress parameter information exhibited by the hazardous element under the target simulation condition based on the target simulation condition identifier; and calculating the principal stress direction of the hazardous element based on the target stress parameter information.
[0074] For example, based on multiple H3D simulation result files, finite element post-processing software can be used to plot the maximum principal stress contour maps and minimum principal stress contour maps of the finite element model. By traversing each critical element in the maximum principal stress contour map, the target maximum principal stress value of the corresponding critical element can be extracted. Combined with the envelope load case information, the simulation load case name corresponding to the critical element with the target maximum principal stress value can be further obtained. Similarly, by traversing each critical element in the minimum principal stress contour map, the target minimum principal stress value of the corresponding critical element can be extracted. Combined with the envelope load case information, the simulation load case name corresponding to the critical element with the target minimum principal stress value can be further obtained.
[0075] Then, the absolute values of the target maximum principal stress and the target minimum principal stress can be compared for each hazardous element. The principal stress value with the larger absolute value is determined as the target principal stress value. The name of the target simulation condition corresponding to the hazardous element with the corresponding target principal stress value can be obtained. Combined with the simulation condition ID list, the corresponding target simulation condition ID can be obtained. Therefore, based on the target simulation condition ID, the target stress parameter information of the hazardous element under the applied target simulation condition can be obtained, and the principal stress direction of the hazardous element under that target simulation condition can be calculated accordingly.
[0076] More specifically, the target stress parameter information can be obtained, for example, from the stress tensor in the H3D simulation results file. The stress tensor can be, for example, Equation (3).
[0077] (3)
[0078] in, , , This constitutes a symmetric tensor.
[0079] Principal stress It is the eigenvalue of the stress tensor, which can be obtained by solving the characteristic equation as shown in formula (4).
[0080] (4)
[0081] Expanding equation (4) yields a cubic equation as shown in equation (5).
[0082] (5)
[0083] in, It is an invariant of the stress tensor and can be expressed as formula (6).
[0084] (6)
[0085] Solving the equation shown in formula (5) yields the three principal stresses. .
[0086] For each principal stress Its corresponding main direction It satisfies formula (7), and the specific equation can be expressed as formula (8).
[0087] (7)
[0088] (8)
[0089] Since the determinant of the coefficient matrix is 0, there are infinitely many solutions to the linear equation system shown in formula (8), which can eventually be solved by normalization ( Determine the unique direction.
[0090] Based on the above method, the principal stress direction can be calculated from the stress tensor of the critical element.
[0091] According to embodiments of this disclosure, a shell element may have a Z1 (positive direction of the normal vector) surface and a Z2 (negative direction of the normal vector) surface. Under complex operating conditions, since the principal stress information of the same shell element on the Z1 surface may differ from its stress parameter information on the Z2 surface, the principal stress directions of each shell element (especially the critical element) on the Z1 surface and on the Z2 surface can be calculated separately based on the above method and recorded for subsequent reference.
[0092] Figure 5 A schematic diagram illustrating a shell unit with the positive direction of the Z-axis as the Z1 plane according to an embodiment of the present disclosure is shown.
[0093] like Figure 5As shown, the shell element 500 includes four nodes, labeled 1, 2, 3, and 4. The shell element 500 itself exists in the xoy plane of the three-dimensional coordinate system. By setting a line from node 1 to node 3 and a line from node 2 to node 4 of the shell element 500, and calculating the normal vector of the shell element 500 based on these two connections, we can obtain that the z-axis direction is the positive direction of this normal vector. Therefore, the z-axis direction can be defined as the Z1 surface of the shell element 500, and the opposite direction of the z-axis can be defined as the Z2 surface of the shell element 500.
[0094] According to embodiments of this disclosure, to support queries, when initializing global variables, an Elem_P_Z1 dictionary can also be established to store the mapping relationship between the shell element ID, the target principal stress value of the Z1 surface, and the principal stress direction of the Z1 surface. Similarly, an Elem_P_Z2 dictionary can be established to store the mapping relationship between the shell element ID, the target principal stress value of the Z2 surface, and the principal stress direction of the Z2 surface.
[0095] According to embodiments of this disclosure, after obtaining the output of calculated data including danger_elem and Elem_P_Z1, Elem_P_Z2, etc., through the aforementioned method, the dangerous element can be determined first based on danger_elem. Then, the process of determining the layout direction of strain gauges for the region where the dangerous element is located based on the principal stress direction can include: in response to determining that the layout surface of the strain gauges for the dangerous region where the dangerous element is located is the Z1 surface, obtaining the principal stress direction of the Z1 surface of the dangerous element according to the Elem_P_Z1 dictionary, and determining the strain gauge layout direction of the dangerous region. In response to determining that the layout surface of the strain gauges for the dangerous region where the dangerous element is located is the Z2 surface, obtaining the principal stress direction of the Z2 surface of the dangerous element according to the Elem_P_Z2 dictionary, and determining the strain gauge layout direction of the dangerous region.
[0096] Through the above embodiments of this disclosure, by comprehensively analyzing the simulation results of multiple working conditions and combining the stress parameter information corresponding to the target principal stress value to calculate the principal stress direction, the strain gauge layout direction at the corresponding position can be determined, which can accurately capture the key stress state and significantly improve the representativeness of the test results and the reliability of the structural safety assessment.
[0097] According to embodiments of this disclosure, before performing the aforementioned operation S150, after obtaining the hazardous element identifier, the shell elements in the finite element model that have the hazardous element identifier can be displayed with a preset rendering effect. Based on this, the location of the hazardous element in the finite element model can be determined according to the display area with the preset rendering effect.
[0098] For example, in preprocessing, based on the dangerous cell ID in `danger_elem`, dangerous cells can be copied to a new part and set to red, such as... Figure 6 As shown, turn off the display of other elements and turn on the display of geometric features to visually display the dangerous areas in the finite element model.
[0099] Figure 6 A schematic diagram illustrating a dangerous area according to an embodiment of the present disclosure is shown.
[0100] like Figure 6 As shown, the red area can represent the danger zone. Therefore, the placement of strain gauges can be determined based on the red area, and further, the placement direction of the strain gauges within the red area can be determined based on the principal stress direction using the methods described above.
[0101] Through the above embodiments of this disclosure, the dangerous area can be intuitively presented on the finite element model using three-dimensional visualization technology, providing data support for the optimized layout of test strain gauges, and significantly improving test efficiency and measurement accuracy.
[0102] Based on the above method, a method for identifying dangerous areas and optimizing strain gauge layout in trains based on finite element simulation can be realized.
[0103] Figure 7 The diagram illustrates the overall flowchart of a train hazard area identification and strain gauge layout optimization method based on finite element simulation according to an embodiment of the present disclosure.
[0104] like Figure 7 As shown, the method includes operations S701 to S715.
[0105] When operating S701, initialize global variables.
[0106] When operating S702, load the finite element model file and simulation result file.
[0107] When operating S703, create an envelope condition.
[0108] In operation S704, obtain the shell unit-node mapping relationship and construct the node-shell unit reverse index.
[0109] When operating S705, determine the welding area and divide it into weld units and base material units.
[0110] When operating S706, set the current envelope condition.
[0111] In operation S707, the material property file is parsed to obtain the allowable stress value of the weld and / or the allowable stress value of the base material.
[0112] In operation S708, draw the Mises stress cloud diagram and extract the Mises stress values of the weld and / or the base material.
[0113] Using S709, draw the maximum principal stress contour plot of the Z1 plane.
[0114] Using S710, draw the minimum principal stress contour plot of the Z1 plane.
[0115] In operation S711, calculate the principal stress values and directions of the target on the Z1 surface.
[0116] Using S712, plot the maximum principal stress contour map of the Z2 plane.
[0117] Using S713, draw the minimum principal stress contour plot of the Z2 plane.
[0118] In operation S714, calculate the principal stress values and directions of the target on the Z2 surface.
[0119] When operating S715, the output calculation data includes: critical element ID, principal stress direction on Z1 plane, and principal stress direction on Z2 plane.
[0120] Through the embodiments described above, multi-condition coupled finite element simulation analysis is introduced. By systematically identifying the simulation results of the vehicle body structure, key stress concentration areas and high-risk failure sites are intelligently identified. This facilitates the establishment of a data-driven, multi-dimensional safety evaluation system, enabling data-driven intelligent safety assessment. It not only significantly improves the relevance of vehicle body test schemes and data acquisition efficiency but also effectively avoids the subjective biases that may exist in traditional experience-based layouts, providing a more scientific and reliable implementation plan for rail vehicle structure testing. Furthermore, by employing three-dimensional visualization mapping technology, digital simulation results can be precisely aligned with the physical model, making the spatial distribution of hazardous areas intuitively visible, which is conducive to achieving a visualization-driven test optimization closed loop.
[0121] Figure 8 A block diagram of a strain gauge layout apparatus according to an embodiment of the present disclosure is shown schematically.
[0122] like Figure 8 As shown, the strain gauge layout device 800 includes a finite element model file acquisition module 810, a weld safety factor calculation module 820, a base material safety factor calculation module 830, a hazardous element determination module 840, and a strain gauge layout position determination module 850.
[0123] The finite element model file acquisition module 810 is used to acquire the finite element model file created based on the object under test. The finite element model file includes shell element information. The shell element information represents the information of multiple shell elements obtained by meshing the finite element model of the object under test. The multiple shell elements are divided into weld elements and base material elements.
[0124] The weld safety factor calculation module 820 is used to calculate the weld safety factor of a weld unit based on the allowable stress value and the Mises stress value of the weld unit.
[0125] The base material safety factor calculation module 830 is used to calculate the base material safety factor of the base material unit based on the allowable stress value and the Mises stress value of the base material unit.
[0126] The hazardous element determination module 840 is used to determine hazardous elements among multiple shell elements based on the weld safety factor and the base material safety factor.
[0127] The strain gauge layout location determination module 850 is used to determine the layout location of the strain gauges in the measured object based on the location of the hazardous element in the finite element model.
[0128] According to embodiments of this disclosure, the finite element model file also includes multiple simulation condition information, which includes the constraints and loads configured for the shell elements in the simulation conditions. The strain gauge placement device also includes a simulation result information calculation module, an envelope condition information determination module, and a Mises stress value acquisition module.
[0129] The simulation result information calculation module is used to calculate at least one simulation result information of the shell element based on the simulation working condition information of the shell element. The simulation result information includes the stress parameter information exhibited by the shell element under the simulation working condition with constraints and loads applied to the shell element. The stress parameter information includes the Mises stress value.
[0130] The envelope condition information determination module is used to determine the envelope condition information of the shell element based on at least one simulation result information, wherein the envelope condition information includes the target Mises stress value with the largest value among at least one Mises stress value from at least one simulation result information.
[0131] The Mises stress value acquisition module is used to determine the Mises stress value of the shell element based on the target Mises stress value, so as to obtain the weld Mises stress value and the base material Mises stress value.
[0132] According to embodiments of this disclosure, the strain gauge layout device further includes a principal stress direction calculation module and a strain gauge layout direction determination module.
[0133] The principal stress direction calculation module is used to calculate the principal stress direction of the hazardous element based on the envelope condition information of the hazardous element.
[0134] The strain gauge layout orientation determination module is used to determine the layout orientation of strain gauges for the area where the hazardous element is located, based on the principal stress direction.
[0135] According to embodiments of this disclosure, the stress parameter information further includes a maximum principal stress value and a minimum principal stress value. The envelope condition information further includes a target maximum principal stress value with the largest absolute value among at least one maximum principal stress value from at least one simulation result information, and a target minimum principal stress value with the largest absolute value among at least one minimum principal stress value from at least one simulation result information. The principal stress direction calculation module includes a target simulation condition identifier acquisition unit, a target stress parameter information determination unit, and a principal stress direction calculation unit.
[0136] The target simulation condition identification acquisition unit is used to obtain the target simulation condition identification of the target simulation condition to which the target principal stress value belongs, based on the target principal stress value with the larger absolute value between the target maximum principal stress value and the target minimum principal stress value of the dangerous unit.
[0137] The target stress parameter information determination unit is used to determine the target stress parameter information exhibited by the hazardous element when the target simulation condition is applied to the hazardous element, based on the target simulation condition identifier.
[0138] The principal stress direction calculation unit is used to calculate the principal stress direction of the critical element based on the target stress parameter information.
[0139] According to embodiments of this disclosure, the finite element model file further includes node identifiers and part names. Node identifiers represent the identifiers of the mesh vertices of the shell elements, and the part names include a profile field representing the profile to which the part belongs and a material field representing the material used in the part. The strain gauge placement device also includes a part name acquisition module and a weld element determination module.
[0140] The part name acquisition module is used to determine multiple related shell units with node identifiers based on node identifiers, and obtain the part name of the part to which each related shell unit belongs, thus obtaining multiple part names.
[0141] The weld element determination module is used to determine multiple related shell elements as weld elements in response to the detection that the profile field or material field in multiple part names is different.
[0142] According to embodiments of this disclosure, the finite element model file further includes a material property file, which includes allowable stress parameters for weld elements and base material elements under different materials and thicknesses. Shell element information includes the actual material and actual thickness of the shell elements. The strain gauge placement device also includes a module for obtaining allowable weld stress values and a module for obtaining allowable base material stress values.
[0143] The module for obtaining allowable stress values for welds is used to parse the material property file based on the actual material and thickness of the weld unit to obtain the allowable stress values for the weld.
[0144] The module for obtaining the allowable stress value of the base material is used to parse the material property file based on the actual material and actual thickness of the base material unit to obtain the allowable stress value of the base material.
[0145] According to embodiments of this disclosure, the hazardous element determination module includes a weld hazardous element determination unit and a base material hazardous element determination unit.
[0146] The weld danger element determination unit is used to determine the weld element as a danger element in response to determining that the weld safety factor meets the first preset condition.
[0147] The base material hazardous element determination unit is used to determine the base material element as a hazardous element in response to determining that the base material safety factor meets the second preset condition.
[0148] According to embodiments of this disclosure, the strain gauge layout device further includes a hazardous element identification acquisition module, a rendering and display module, and a hazardous element location determination module.
[0149] The hazardous unit identifier acquisition module is used to acquire the hazardous unit identifier of hazardous units.
[0150] The rendering and display module is used to display shell elements with dangerous element markers in the finite element model using preset rendering effects.
[0151] The hazardous element location determination module is used to determine the location of hazardous elements in the finite element model based on the display area with preset rendering effects in the finite element model.
[0152] Any one or more of the modules or units according to embodiments of this disclosure, or at least part of the functions of any one or more of them, can be implemented in one module. Any one or more of the modules or units according to embodiments of this disclosure can be implemented by dividing them into multiple modules. Any one or more of the modules or units according to embodiments of this disclosure can be at least partially implemented as hardware circuitry, such as a Field-Programmable Gate Array (FPGA), a Programmable Logic Array (PLA), a System-on-Chip, a System-on-Substrate, a System-on-Package, an Application-Specific Integrated Circuit (ASIC), or implemented by hardware or firmware in any other reasonable manner by integrating or packaging the circuitry, or implemented in any one of software, hardware, and firmware, or in a suitable combination of any of these. Alternatively, one or more of the modules or units according to embodiments of this disclosure can be at least partially implemented as computer program modules, which, when run, can perform corresponding functions.
[0153] For example, any and multiple modules among the finite element model file acquisition module 810, weld safety factor calculation module 820, base material safety factor calculation module 830, hazardous element determination module 840, and strain gauge layout location determination module 850 can be combined into one module / unit, or any one of these modules / units can be split into multiple modules / units. Alternatively, at least some of the functions of one or more of these modules / units can be combined with at least some of the functions of other modules / units and implemented in one module / unit. According to embodiments of this disclosure, at least one of the finite element model file acquisition module 810, weld safety factor calculation module 820, base material safety factor calculation module 830, hazardous element determination module 840, and strain gauge layout location determination module 850 can be at least partially implemented as hardware circuits, such as field-programmable gate arrays (FPGAs), programmable logic arrays (PLAs), systems-on-a-chip, systems-on-a-substrate, systems-on-package, application-specific integrated circuits (ASICs), or any other reasonable means of integrating or packaging circuits, or implemented in software, hardware, or firmware, or in any suitable combination of any of these three implementation methods. Alternatively, at least one of the finite element model file acquisition module 810, weld safety factor calculation module 820, base material safety factor calculation module 830, hazardous element determination module 840, and strain gauge layout location determination module 850 can be at least partially implemented as computer program modules, which can perform corresponding functions when the computer program module is run.
[0154] It should be noted that the strain gauge layout device in the embodiments of this disclosure corresponds to the strain gauge layout method in the embodiments of this disclosure. For a detailed description of the strain gauge layout device, please refer to the strain gauge layout method section, which will not be repeated here.
[0155] This disclosure also provides a train in which strain gauges are arranged, the arrangement of which is determined based on the method described above.
[0156] Figure 9 A block diagram of an electronic device suitable for implementing a strain gauge layout method according to an embodiment of the present disclosure is shown schematically. Figure 9 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments disclosed herein.
[0157] like Figure 9As shown, an electronic device 900 according to an embodiment of the present disclosure includes a processor 901, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 902 or a program loaded from a storage portion 908 into a random access memory (RAM) 903. The processor 901 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 901 may also include onboard memory for caching purposes. The processor 901 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present disclosure.
[0158] RAM 903 stores various programs and data required for the operation of electronic device 900. Processor 901, ROM 902, and RAM 903 are interconnected via bus 904. Processor 901 performs various operations of the method flow according to embodiments of the present disclosure by executing programs in ROM 902 and / or RAM 903. It should be noted that the programs may also be stored in one or more memories other than ROM 902 and RAM 903. Processor 901 may also perform various operations of the method flow according to embodiments of the present disclosure by executing programs stored in said one or more memories.
[0159] According to embodiments of this disclosure, the electronic device 900 may further include an input / output (I / O) interface 905, which is also connected to a bus 904. The electronic device 900 may also include one or more of the following components connected to the input / output (I / O) interface 905: an input section 906 including a keyboard, mouse, etc.; an output section 907 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 908 including a hard disk, etc.; and a communication section 909 including a network interface card such as a LAN card, modem, etc. The communication section 909 performs communication processing via a network such as the Internet. A drive 910 is also connected to the input / output (I / O) interface 905 as needed. A removable medium 911, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the drive 910 as needed so that computer programs read from it can be installed into the storage section 908 as needed.
[0160] According to embodiments of this disclosure, the method flow according to embodiments of this disclosure can be implemented as a computer software program. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable storage medium, the computer program containing program code for performing the methods shown in the flowchart. In such embodiments, the computer program can be downloaded and installed from a network via communication section 909, and / or installed from removable medium 911. When the computer program is executed by processor 901, it performs the functions defined in the system of embodiments of this disclosure. According to embodiments of this disclosure, the systems, devices, apparatuses, modules, units, etc., described above can be implemented by computer program modules.
[0161] This disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into the device / apparatus / system. The computer-readable storage medium carries one or more programs, which, when executed, implement the strain gauge placement method according to the embodiments of this disclosure.
[0162] According to embodiments of this disclosure, the computer-readable storage medium can be a non-volatile computer-readable storage medium. Examples include, but are not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this disclosure, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.
[0163] For example, according to embodiments of this disclosure, a computer-readable storage medium may include the ROM 902 and / or RAM 903 described above and / or one or more memories other than ROM 902 and RAM 903.
[0164] Embodiments of this disclosure also include a computer program product comprising a computer program containing program code for performing the methods provided in the embodiments of this disclosure. When the computer program product is run on an electronic device, the program code is used to enable the electronic device to implement the strain gauge layout method provided in the embodiments of this disclosure.
[0165] When the computer program is executed by the processor 901, it performs the functions defined in the system / apparatus of this disclosure embodiments. According to embodiments of this disclosure, the systems, apparatuses, modules, units, etc., described above can be implemented by computer program modules.
[0166] In one embodiment, the computer program may rely on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may also be transmitted and distributed in the form of signals over a network medium, and downloaded and installed via the communication section 909, and / or installed from a removable medium 911. The program code contained in the computer program can be transmitted using any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination thereof.
[0167] According to embodiments of this disclosure, program code for executing the computer programs provided in embodiments of this disclosure can be written in any combination of one or more programming languages. Specifically, these computational programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages include, but are not limited to, languages such as Java, C++, Python, "C", or similar programming languages. The program code can execute entirely on a user's computing device, partially on a user's device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).
[0168] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions. Those skilled in the art will understand that the features described in the various embodiments of the present disclosure can be combined and / or combined in various ways, even if such combinations are not explicitly described in the present disclosure. In particular, the features described in the various embodiments of this disclosure may be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.
[0169] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.
Claims
1. A strain gauge layout method, comprising: Obtain a finite element model file created based on the object under test. The finite element model file includes shell element information. The shell element information represents the information of multiple shell elements obtained by meshing the finite element model of the object under test. The multiple shell elements are divided into weld elements and base material elements. The weld safety factor of the weld unit is calculated based on the allowable stress value and the Mises stress value of the weld unit. The base material safety factor of the base material unit is calculated based on the allowable stress value and the Mises stress value of the base material unit. Based on the weld safety factor and the base material safety factor, the hazardous elements among the plurality of shell elements are determined; Based on the location of the hazardous element in the finite element model, the layout position of the strain gauges in the object under test is determined.
2. The method according to claim 1, wherein, The finite element model file also includes multiple simulation condition information, which includes the constraints and loads configured for the shell element in the simulation. The method further includes: Based on the simulation working condition information of the shell element, at least one simulation result information of the shell element is calculated, wherein the simulation result information includes stress parameter information exhibited by the shell element under the simulation working condition with the constraint conditions and the load, and the stress parameter information includes the Mises stress value. Based on the at least one simulation result information, the envelope condition information of the shell element is determined, wherein the envelope condition information includes the target Mises stress value with the largest value among at least one Mises stress value of the at least one simulation result information. Based on the target Mises stress value, the Mises stress value of the shell unit is determined to obtain the weld Mises stress value and the base material Mises stress value.
3. The method according to claim 2, further comprising: Based on the envelope condition information of the hazardous element, calculate the principal stress direction of the hazardous element; Based on the principal stress direction, determine the layout direction of the strain gauges located in the area where the hazardous unit is situated.
4. The method according to claim 3, wherein, The stress parameter information also includes the maximum principal stress value and the minimum principal stress value. The envelope condition information also includes the target maximum principal stress value with the largest absolute value among the at least one maximum principal stress value of the at least one simulation result information, and the target minimum principal stress value with the largest absolute value among the at least one minimum principal stress value of the at least one simulation result information. The step of calculating the principal stress direction of the hazardous element based on the envelope condition information of the hazardous element includes: Based on the target principal stress value with the larger absolute value between the target maximum principal stress value and the target minimum principal stress value of the dangerous unit, obtain the target simulation condition identifier of the target simulation condition to which the target principal stress value belongs; Based on the target simulation condition identifier, determine the target stress parameter information of the hazardous unit when the target simulation condition is applied to the hazardous unit; Based on the target stress parameter information, calculate the principal stress direction of the hazardous unit.
5. The method according to claim 1, wherein, The finite element model file also includes node identifiers and part names. The node identifiers represent the identifiers of the mesh vertices of the shell element, and the part names include a profile field representing the profile to which the part belongs and a material field representing the material used in the part. The method also includes: Based on the node identifier, determine multiple related shell units with the node identifier, and obtain the part name of the part to which each related shell unit belongs, thus obtaining multiple part names; In response to the detection that the profile field or material field in the plurality of part names is different, the plurality of related shell units are identified as the weld unit.
6. The method according to claim 1, wherein, The finite element model file also includes a material property file, which includes allowable stress parameters for weld elements and base material elements under different materials and thicknesses. The shell element information includes the actual material and actual thickness of the shell element. The method further includes: Based on the actual material and actual thickness of the weld unit, the material property file is parsed to obtain the allowable stress value of the weld. Based on the actual material and actual thickness of the base material unit, the material property file is parsed to obtain the allowable stress value of the base material.
7. The method according to claim 1, wherein, The step of determining the hazardous element among the plurality of shell elements based on the weld safety factor and the base material safety factor includes: In response to determining that the safety factor of the weld meets the first preset condition, the weld unit is identified as the dangerous unit; In response to determining that the safety factor of the base material meets the second preset condition, the base material unit is identified as the dangerous unit.
8. The method according to claim 1, further comprising: Obtain the hazardous unit identifier of the hazardous unit; The shell elements with the dangerous element identifier in the finite element model are displayed with a preset rendering effect; The location of the hazardous element in the finite element model is determined based on the display area with the preset rendering effect in the finite element model.
9. The method according to any one of claims 1-8, wherein, The hazardous unit includes a shell unit determined according to a preset area.
10. A type of train, wherein, Strain gauges are arranged in the train, and the arrangement of the strain gauges is determined based on the method described in any one of claims 1-9.