A cross-platform model transfer method combining CATIA and MIDAS

Abstract

This invention discloses a cross-platform model transfer method combining CATIA and MIDAS. The method generates a skeleton model containing node, element, cross-section, and material information based on an engineering design scheme in CATIA. It then uses an EKL script to automatically extract model data and store it in a standardized skeleton information table (node ​​information includes coordinates and spacing; element / cross-section / material information is converted to MIDAS-compatible MCT format strings). A Python script then reads the table data to generate an MCT file, which is finally imported into MIDAS to complete model construction and structural analysis. For scenarios involving multiple scheme comparisons, unique labels are added to the skeleton models of different design schemes. After unifying boundary conditions and load cases, the optimal scheme is quickly selected based on the calculation and analysis results.

Description

Technical Field

[0001] This invention relates to the field of engineering design and structural analysis technology, specifically to a cross-platform model transfer method combining CATIA and MIDAS. Background Technology

[0002] In the fields of engineering design and structural analysis, CATIA, as a mainstream 3D design software, is often used to quickly build skeleton models of complex structures, while MIDAS is a professional structural analysis software that requires mechanical calculations based on accurate model parameters. However, the current model transfer between CATIA and MIDAS faces the following technical bottlenecks:

[0003] Traditional model data transfer relies on manual extraction and format conversion. Information such as node coordinates, unit connection relationships, cross-sectional parameters and material properties of the skeleton model in CATIA must be manually entered into MIDAS one by one. This is inefficient and prone to data errors due to human operation. Especially when dealing with engineering models with a large number of nodes and complex structures, manual processing is costly and it is difficult to ensure data integrity.

[0004] In addition, the data format compatibility between different software is insufficient. CATIA's geometric model data cannot be directly recognized by MIDAS and needs to be converted through an intermediate format. However, the existing conversion methods often face problems such as information loss or format mismatch. For example, key information such as cross-section type and material parameters are difficult to transmit directly during the transmission process, which affects the accuracy and efficiency of structural analysis results.

[0005] In scenarios involving comparison of multiple schemes, traditional methods require repeated modeling and parameter setting for each design scheme, which cannot quickly achieve unified configuration of boundary conditions and load conditions. This results in a long scheme comparison cycle and makes it difficult to intuitively compare the differences in mechanical performance between different designs, thus restricting the optimization efficiency of engineering design.

[0006] Existing technologies lack an automated, high-precision cross-platform model transfer mechanism, making it difficult to meet the needs of rapid modeling and efficient multi-scheme analysis in engineering design. Therefore, there is an urgent need to propose an automated model transfer method combining CATIA and MIDAS to solve problems such as low data transfer efficiency, poor accuracy, and difficulty in comparing multiple schemes, thereby improving the integration level of engineering design and analysis. Summary of the Invention

[0007] The purpose of this invention is to provide a cross-platform model transfer method that combines CATIA and MIDAS, thereby solving the problems mentioned in the background art.

[0008] This invention is achieved through the following technical solution:

[0009] A cross-platform model transfer method combining CATIA and MIDAS includes automatically generating a blank skeleton information table from a skeleton model generated in CATIA based on an engineering design scheme. The skeleton information includes node information, element information, cross-section information, and material information. The specific steps are as follows:

[0010] S1.CATIA automatically extracts node information and element information of skeleton model nodes through EKL language scripts, and stores the node information in the skeleton information table, while the element information is stored in the skeleton information table in MCT format string format.

[0011] S2.CATIA uses EKL language scripts to extract the corresponding section information and material information according to the section number in the section information in the MIDAS MCT format, and generates MCT format strings for the section information and material information corresponding to the section number respectively and stores them in the skeleton information table.

[0012] S3.Python uses all the data in the skeleton information table generated by CATIA to automatically generate a command stream that MIDAS can recognize, which contains node information, element information, section information and material information. The command stream is saved as an MCT file.

[0013] S4.CATIA transmits the MCT file to MIDAS. MIDAS generates the corresponding skeleton model based on the MCT file, adds boundary conditions and load cases, and performs structural analysis and calculations to obtain results for evaluating the corresponding skeleton model.

[0014] Furthermore, when it is necessary to compare various design schemes of similar skeleton models and select the best scheme, this includes:

[0015] Generate corresponding skeleton models for each design scheme according to the parameters of different design schemes, and add unique labels to the generated skeleton models. Obtain the skeleton models corresponding to the labels in MIDAS according to the S2 to S4 method. After setting the boundary conditions and load cases of each scheme skeleton model to be consistent, calculate the internal forces and displacements of each scheme skeleton model to obtain the calculation results of each skeleton model. Compare the calculation results to obtain the optimal scheme.

[0016] Furthermore, the calculation results include: maximum internal force value, maximum displacement value, and stress distribution.

[0017] Furthermore, the node information includes the node number, the spatial coordinates of the node in CATIA along the X, Y, and Z axes, and the node spacing.

[0018] Furthermore, the skeleton information table is automatically generated and has a header, which includes: node number and X-axis, Y-axis, Z-axis, node spacing, unit information, cross-section information, and material information fields.

[0019] Furthermore, the unit information includes unit number, coordinates of the unit's starting end connected to other node numbers, coordinates of the unit's ending end connected to other node numbers, unit type, and unit length. The string format of the unit information is "unit number, coordinates of the unit's starting end connected to other node numbers, coordinates of the unit's ending end connected to other node numbers, unit type, unit length".

[0020] Furthermore, the cross-sectional information includes cross-sectional number, cross-sectional type, cross-sectional width, and cross-sectional height. The cross-sectional information is generated as an MCT format string of "cross-sectional number, cross-sectional type, cross-sectional width, and cross-sectional height".

[0021] Furthermore, the material information includes material type, Poisson's ratio, elastic modulus, and Young's modulus. The string generated by the material information is "material type, Poisson's ratio, elastic modulus, Young's modulus".

[0022] The beneficial effects of this invention are as follows:

[0023] 1. To address the issues of low efficiency and error-proneness in data extraction and conversion during traditional model transfer, this method automatically extracts node, element, section, and material information from CATIA skeleton models using EKL language scripts and stores it in a standardized format in a table. This avoids the inefficiency and errors of manual input, achieving lossless transfer of geometric data and physical properties, and laying an accurate foundation for subsequent analysis.

[0024] 2. Utilize Python scripts to automatically generate MCT files that MIDAS can recognize, eliminating the need for manual data format conversion and establishing a seamless model transfer link between CATIA and MIDAS. MCT files organize data according to standardized structures such as NODE, ELEMENT, and SECTION_BEAM, ensuring complete mapping of node coordinates, element connections, section parameters, and material properties, thus improving model transfer efficiency and accuracy.

[0025] 3. In scenarios comparing multiple schemes using similar skeleton models, by adding unique labels to each scheme's skeleton model and combining them with unified boundary conditions and load case settings, MIDAS analysis models for each scheme can be quickly generated. Based on standardized calculations of maximum internal force, maximum displacement, stress distribution, and other results, the performance differences between different design schemes can be intuitively compared, avoiding interference from external factors, ensuring the scientific validity and fairness of the comparison results, and significantly shortening the design iteration cycle. This is particularly suitable for engineering scenarios requiring rapid verification of different spans and cross-sectional forms.

[0026] 4. The skeleton information table uses standardized header fields (such as node number, X / Y / Z axis coordinates, node spacing, etc.) to ensure a consistent data format, facilitating Python scripts to read data using fixed column indices and reducing the risk of parsing errors. Simultaneously, the structured data storage method of the MCT file provides traceability for model parameters, enabling engineers to verify the accuracy of unit connection relationships, cross-sectional dimensions, and material parameters, thereby improving the efficiency of model quality control. Attached Figure Description

[0027] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0029] See the example. Figure 1 :

[0030] A cross-platform model transfer method combining CATIA and MIDAS includes automatically generating a blank skeleton information table from a skeleton model generated in CATIA based on an engineering design scheme. The skeleton information includes node information, element information, cross-section information, and material information. The specific steps are as follows:

[0031] S1.CATIA automatically extracts node information and element information of skeleton model nodes through EKL language scripts, and stores the node information in the skeleton information table, while the element information is stored in the skeleton information table in MCT format string format.

[0032] S2.CATIA uses EKL language scripts to extract the corresponding section information and material information according to the section number in the section information in the MIDAS MCT format, and generates MCT format strings for the section information and material information corresponding to the section number respectively and stores them in the skeleton information table.

[0033] S3.Python uses all the data in the skeleton information table generated by CATIA to automatically generate a command stream that MIDAS can recognize, which contains node information, element information, section information and material information. The command stream is saved as an MCT file.

[0034] S4.CATIA transmits the MCT file to MIDAS. MIDAS generates the corresponding skeleton model based on the MCT file, adds boundary conditions and load cases, and performs structural analysis and calculations to obtain results for evaluating the corresponding skeleton model.

[0035] This invention generates a skeleton model containing node, element, section, and material information based on an engineering design scheme in CATIA and automatically generates a blank skeleton information table. It then uses an EKL script to extract node information (including node number, X / Y / Z axis coordinates, and node spacing) and element information (including element number, start and end node coordinates, element type, and length, stored as an MCT format string). Finally, it extracts section information (including section number, type, width, and height) and material information (including material type, Poisson's ratio, elastic modulus, and Young's modulus) according to MIDAS's MCT format, generating MC... The T-format string is stored in a table. A Python script reads the table data to generate an MCT file containing node, element, section, and material information. This file is then imported into MIDAS to generate a skeleton model. Boundary conditions and load cases are added, and structural analysis calculations are performed to obtain results such as maximum internal force, maximum displacement, and stress distribution to evaluate the model. When it is necessary to compare different design schemes of similar skeleton models, a corresponding skeleton model is generated according to the parameters of each scheme and a unique label is added. After unifying the boundary conditions and load cases in MIDAS according to the above process, the internal forces and displacements of each scheme are calculated. The optimal scheme is selected based on the comparison of the results.

[0036] In MIDAS, nodes are created based on the node number and node coordinates in the node information of the MCT file. Then, the nodes connecting the elements are confirmed based on the beam element information, and the relationship between the elements and each node is established to form a preliminary beam element topology.

[0037] Finally, based on the section information and material information, the corresponding section is selected from the section library of the MIDAS software and accurately assigned to each of the previously defined beam elements to determine the cross-sectional geometric properties of the beam elements. Similarly, based on the material properties specified in the material information, such as elastic modulus and Poisson's ratio, the corresponding material is selected from the software material library and associated with the corresponding beam element to give the beam element complete material properties, thus obtaining the final complete skeleton model.

[0038] The MCT format consists of NODE, ELEMENT, SECTION_BEAM, and TYPE_BEAM sequences. NODE represents a node, followed by node information; ELEMENT represents an element, followed by element information; SECTION_BEAM and TYPE_BEAM are grouped together, with section information and corresponding material information following them, as detailed below:

[0039]

[0040] Furthermore, when it is necessary to compare various design schemes of the same skeleton model and select the best scheme, the process includes: generating corresponding skeleton models for each scheme according to the parameters of different design schemes, adding unique labels to the generated skeleton models, obtaining skeleton models corresponding to the labels in MIDAS according to S2 to S4, calculating the internal forces and displacements of each skeleton model after setting the boundary conditions and load cases of each scheme skeleton model to be consistent, obtaining the calculation results of each skeleton model, and comparing the calculation results to obtain the best scheme.

[0041] When comparing multiple schemes, adding unique labels to the skeleton models of each design scheme enables clear differentiation and management of these schemes within MIDAS. This ensures consistency in boundary conditions and load cases, avoids deviations in calculation results due to differences in external factors, and guarantees the scientific rigor and fairness of scheme selection. It improves the efficiency of parallel analysis of multiple schemes, shortens the design iteration cycle, and is particularly suitable for engineering scenarios requiring rapid verification of different spans and cross-sectional forms.

[0042] In one embodiment, during the preliminary design of a steel truss bridge, three schemes with spans of 50 meters, 60 meters, and 70 meters were designed. Corresponding skeleton models were quickly generated in CATIA based on different span parameters, and each model was labeled (e.g., Scheme A, Scheme B, Scheme C). After extracting the node coordinates, element connection relationships, and section information for each scheme using an EKL script, labeled MCT files were generated using a Python script and imported into MIDAS. In MIDAS, the same boundary constraints were uniformly set, such as fixed supports at both ends and a uniformly distributed load condition of 50 kN / m. The internal forces, displacements, and material requirements of each scheme were calculated, and the optimal scheme was ultimately determined.

[0043] Furthermore, the calculation results include: maximum internal force value, maximum displacement value, and stress distribution.

[0044] Furthermore, the node information includes the node number, the spatial coordinates of the node in CATIA along the X, Y, and Z axes, and the node spacing.

[0045] Spatial coordinates (X / Y / Z axes) form the geometric foundation of the skeleton model, ensuring complete spatial consistency between the CATIA and MIDAS models. Node spacing is used to verify the rationality of element lengths and assist in checking modeling errors. EKL scripts automatically extract and write these data, avoiding the inefficiency and errors of manual coordinate input, achieving lossless transfer of geometric data, and laying a precise foundation for subsequent analysis.

[0046] In one embodiment, in a CATIA model of a bridge, the coordinates of node E1 are (837765mm, 0mm, 7362.0912mm), and the distance between it and the adjacent node E2 is 2200mm. These data are written into the corresponding rows of the skeleton information table, such as node 1 corresponding to X=837765, Y=0, Z=7362.0912, with a distance of 2200.

[0047] The Python script reads and generates the node information statement "1, 8377650, 7362.0912" in the MCT file, ensuring that the node positions in MIDAS are completely consistent with those in CATIA, and avoiding unit connection errors caused by coordinate deviations.

[0048] Furthermore, the skeleton information table is automatically generated and has a header, which includes: node number and X-axis, Y-axis, Z-axis, node spacing, unit information, cross-section information, and material information fields.

[0049] Standardized header fields such as “node number”, “X (mm)”, “Y (mm)”, “Z (mm)”, and “node spacing” unify the data format, make the table structure clear, and facilitate Python scripts to read data according to fixed column indices, reducing the risk of parsing errors caused by messy headers.

[0050] In one embodiment, before running the EKL script in CATIA, a file with standardized headers needs to be created beforehand. When the script executes, it automatically fills in the node number in column A, the X coordinate in column B, the Y coordinate in column C, the Z coordinate in column D, and the node spacing in column E. For example, the information for node E3 corresponds to row 3 of the table: A3="E3", B3=823166, C3=0, D3=7229.9866, E3=7300. The Python script generates the MCT node coordinates by reading the data in columns B, C, and D, and verifies the cell length by reading column E, ensuring data integrity. When reading the node number, only the "3" in the node number "E3" needs to be read.

[0051] Furthermore, the unit information includes unit number, coordinates of the unit's starting end connected to other node numbers, coordinates of the unit's ending end connected to other node numbers, unit type, and unit length. The string format of the unit information is "unit number, coordinates of the unit's starting end connected to other node numbers, coordinates of the unit's ending end connected to other node numbers, unit type, unit length".

[0052] The string corresponding to the element information clearly defines the element number, element start / end node, element type, and element length, and is fully compatible with MIDAS's MCT syntax. This format ensures that Python scripts can directly parse and generate ELEMENT commands, avoiding model generation failures due to format inconsistencies. It also facilitates engineers in quickly verifying the correctness of element connection relationships, such as "1,1,2,TYPE_BEAM,2200".

[0053] In one embodiment, in the CATIA skeleton model, a beam element connects node 1 and node 2, with element number 1 and a length of 2200mm. The EKL script converts this into the string "1, 1, 2, TYPE_BEAM, 2200" and stores it in the skeleton information table. The first 1 indicates that this is the first beam element number, the second 1 indicates that the start end of the beam element is connected to node number 1, and the third 1 indicates that the end end of the beam element is connected to node number 2. TYPE_BEAM indicates that this is a beam element, and 2000 indicates that the length of the beam element is 2.2mm. After importing into MIDAS, the beam element connecting node 1 and node 2 is automatically generated, with the length consistent with the CATIA model, without the need for manual adjustment.

[0054] Furthermore, the cross-sectional information includes cross-sectional number, cross-sectional type, cross-sectional width, and cross-sectional height. The cross-sectional information is generated as an MCT format string of "cross-sectional number, cross-sectional type, cross-sectional width, and cross-sectional height".

[0055] Standardized section parameter strings such as "1,RECTANGLE,0.3,0.5" directly adapt to MIDAS's SECTION_BEAM command, ensuring accurate transmission of section type and dimensions. This avoids analysis errors caused by ambiguous section parameter descriptions and also supports MIDAS's automatic calculation of section geometric properties, improving analysis efficiency.

[0056] In one embodiment, taking a box-shaped section as an example, the section number in CATIA is 1, with a width of 0.3 meters and a height of 0.5 meters. An EKL script generates the string "1,RECTANGLE,0.3,0.5" and stores it. A Python script reads this and generates the MCT statement `SECTION_BEAM1,RECTANGLE,0.3,0.5`. MIDAS creates a rectangular section based on this statement, automatically calculating the area as 0.3 × 0.5 = 0.15 m² and the moment of inertia as 0.3 × 0.5³ / 12 ≈ 0.003125 m. 4 It is used for subsequent internal force and stiffness calculations.

[0057] Furthermore, the material information includes material type, Poisson's ratio, elastic modulus, and Young's modulus. The string generated by the material information is "material type, Poisson's ratio, elastic modulus, Young's modulus".

[0058] The material information string, such as "MAT_Steel,0.3,2.06E5,2.06E5", clearly defines the core physical properties such as the material name, Poisson's ratio, and elastic modulus. This ensures that MIDAS correctly applies the material constitutive relationship in structural analysis and avoids calculation distortion caused by missing or incorrect material parameters. It is especially suitable for scenarios involving comparison of multiple schemes for complex materials.

[0059] In one embodiment, for steel, CATIA extracts a Poisson's ratio of 0.3 and an elastic modulus of 2.06 × 10⁻⁶. 5 MPa. The EKL script generates the string "MAT_Steel,0.3,2.06E5,2.06E5" and stores it in a table. The Python script reads this and generates the MCT statement `MAT_Steel,0.3,2.06E5,2.06E5`. MIDAS applies this statement to all associated elements, accurately reflecting material deformation characteristics when calculating stress, ensuring the reliability of internal force calculation results. The final skeleton information table is shown in Table 1 below.

[0060]

[0061] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A cross-platform model transfer method combining CATIA and MIDAS, characterized in that, This includes automatically generating a blank, standardized skeleton information table from the skeleton model generated by CATIA based on the engineering design scheme. The skeleton information includes node information, element information, section information, and material information. The specific steps are as follows: S1.CATIA automatically and synchronously extracts node information and element information of skeleton model nodes through EKL language scripts, and stores the node information in the skeleton information table, while the element information is stored in the skeleton information table in the form of MCT format strings that conform to the ELEMENT segment syntax of MIDAS. S2.CATIA uses the section number in the section information as the hub through the EKL language script, extracts the corresponding section information according to the MIDAS MCT format, and generates MCT format strings for the section information and material information corresponding to the section number, and stores them in the skeleton information table. S3.Python uses all the associated data in the skeleton information table generated by CATIA to automatically generate a complete command stream that MIDAS can recognize, containing node information, element information, section information and material information, in the sequence of NODE, ELEMENT, SECTION_BEAM and TYPE_BEAM. The command stream is saved as an MCT file. S4.CATIA transmits the MCT file to MIDAS. MIDAS generates the corresponding skeleton model based on the MCT file, adds boundary conditions and load cases, and performs structural analysis and calculations to obtain results for evaluating the corresponding skeleton model.

2. The cross-platform model transfer method combining CATIA and MIDAS according to claim 1, characterized in that, When it is necessary to compare various design schemes of similar skeleton models and select the best scheme, this includes: Generate corresponding skeleton models for each design scheme according to the parameters of different design schemes, and add unique labels to the generated skeleton models. Obtain the skeleton models corresponding to the labels in MIDAS according to the S2 to S4 method. After setting the boundary conditions and load cases included in the skeleton models of each scheme to be consistent, calculate the internal forces and displacements of the skeleton models of each scheme to obtain the calculation results of each skeleton model. The optimal scheme is obtained by comparing the calculation results.

3. The cross-platform model transfer method combining CATIA and MIDAS according to claim 2, characterized in that, The calculation results include: maximum internal force value, maximum displacement value, and stress distribution.

4. The cross-platform model transfer method combining CATIA and MIDAS according to claim 1, characterized in that, The node information includes the node number, the spatial coordinates of the node in CATIA along the X, Y, and Z axes, and the node spacing.

5. The cross-platform model transfer method combining CATIA and MIDAS according to claim 4, characterized in that, The skeleton information table is automatically generated and has a header, which includes: node number and X-axis, Y-axis, Z-axis, node spacing, element information, cross-section information, and material information fields.

6. The cross-platform model transfer method combining CATIA and MIDAS according to claim 1, characterized in that, The unit information includes unit number, coordinates of the unit's starting end to other node numbers, coordinates of the unit's ending end to other node numbers, unit type, and unit length. The string format of the unit information is "unit number, coordinates of the unit's starting end to other node numbers, coordinates of the unit's ending end to other node numbers, unit type, unit length".

7. The cross-platform model transfer method combining CATIA and MIDAS according to claim 1, characterized in that, The cross-sectional information includes cross-sectional number, cross-sectional type, cross-sectional width, and cross-sectional height. The cross-sectional information is generated as an MCT format string of "cross-sectional number, cross-sectional type, cross-sectional width, cross-sectional height".

8. The cross-platform model transfer method combining CATIA and MIDAS according to claim 1, characterized in that, The material information includes material type, Poisson's ratio, elastic modulus, and Young's modulus. The string generated by the material information is "material type, Poisson's ratio, elastic modulus, Young's modulus".

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