A rapid skeleton modeling method based on CATIA

Abstract

The present invention discloses a rapid skeleton modeling method based on CATIA, which realizes the automatic modeling of steel truss skeleton through the bridge parameter EXCEL table and encapsulated UDF. The steps include: using the EKL language to call the parameter table data, batch generating and numbering the upper / lower chord nodes, generating chords, webs and transverse connection lines, constructing a geometric graphics set and calling the UDF to generate an envelope model, and supporting parameter modification and rapid iteration of the model. The nodes and components are numbered in a structured manner, and the associated section parameter library is used for rapid replacement. The UDF includes sweep and section functions, and the entity generation is driven by the sub-geometric graphics set. The node plate is automatically generated by the chord / web connection line. This method improves the modeling efficiency and parameterization level, and is suitable for the rapid design of steel truss bridges with different structural forms.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering design and structural analysis, and in particular to a CATIA-based rapid skeleton modeling method. Background Art

[0002] In bridge engineering, steel truss structures are widely used due to their excellent mechanical properties and strong spanning capacity. The rapid development of transportation infrastructure construction has placed higher demands on the design efficiency and refined modeling of steel truss bridges. CATIA, as an advanced computer-aided design software, offers powerful capabilities for modeling complex structures. However, traditional steel truss skeleton modeling methods have significant limitations.

[0003] In existing technologies, steel truss skeleton modeling typically relies on manual component-by-component creation, requiring repeated operations such as node positioning and rod connection, making the modeling process cumbersome and time-consuming. For bridge structures with different spans, truss heights, truss spacing, or curved forms, a large amount of repetitive work must be redone, making parameter modification and structural form adjustment difficult, making it difficult to meet the needs of rapid iteration and multiple scheme comparisons during the design phase. Furthermore, traditional methods lack sufficient correlation between geometric figures and envelope models, and lack systematic parameter management and automated generation mechanisms, resulting in low modeling efficiency and the vulnerability of model accuracy to human error.

[0004] Therefore, leveraging CATIA's parametric design capabilities to rapidly generate and flexibly adjust steel truss skeleton models has become a pressing technical challenge in the field of digital bridge modeling. This paper proposes a CATIA-based rapid skeleton modeling method. By integrating bridge parameter Excel spreadsheets and encapsulating UDFs (User Defined Features), combined with the EKL language, this method enables parameter-driven and batch modeling. This approach aims to overcome the efficiency bottlenecks of traditional modeling methods and provide technical support for the efficient design of steel truss bridges. Summary of the Invention

[0005] The purpose of the present invention is to provide a CATIA-based rapid skeleton modeling method to solve the problems in the above-mentioned background technology.

[0006] The present invention is achieved through the following technical solutions:

[0007] A CATIA-based rapid skeleton modeling method includes an EXCEL table of bridge parameters and a packaged UDF. The EXCEL table of bridge parameters includes parameters such as span length, girder height, girder spacing, whether the girder is curved, and upper node layout parameters and lower node layout parameters. The specific steps are as follows:

[0008] S1.CATIA uses EKL language to call the parameters in the bridge parameter EXCEL table to the CATIA parameter set for standby use;

[0009] S2.CATIA reads the parameters in the parameter set and runs out the upper and lower chord nodes in batches using the EKL language, and numbers each upper and lower chord node;

[0010] S3. Connect the upper chord lines according to the order in which the upper chord nodes are batched out, and connect the lower chord lines according to the order in which the lower chord nodes are batched out, and number the upper chord lines and lower chord lines for each.

[0011] S4. Use the EKL language to obtain the numbers of all upper and lower chord nodes and store them in the second and third columns of the Excel spreadsheet to form a node table. Then, based on the layout principles of the web lines, combine the numbers of the upper and lower chord nodes to be connected in the node table and place them in the first column. Use the EKL language to call the combination numbers in the first column, generate web lines based on the combination numbers, and name them in the combination number field.

[0012] S5. Obtain the names of the two upper chord nodes or the two lower chord nodes through the EKL language pre-compiled horizontal connection layout principle, and connect them to generate horizontal connection lines;

[0013] S6. Take all upper and lower chord nodes, upper and lower chord lines, web lines, and transverse lines as input lines, and use the upper or lower chord node as the base point in the first-level geometric shape set. Find the upper chord lines, lower chord lines, web lines, and transverse lines in the input lines that satisfy the relationship with the base point defined in the EKL language, and place the base point and the upper chord lines, lower chord lines, web lines, and transverse lines that satisfy the relationship in the second-level geometric shape set named after the base point.

[0014] S7. Based on the sub-geometry set in S6, the corresponding UDF is called to generate an envelope model of the chord, web, and transverse connection to obtain a steel truss skeleton model;

[0015] S8. Modify the bridge parameter EXCEL table and re-run the script to quickly update and generate the steel truss skeleton model.

[0016] Further,

[0017] The node numbers of the upper chord nodes and the lower chord nodes are in the form of "A+i" and "E+i" respectively, where i is a number.

[0018] Further,

[0019] The upper chord line and the lower chord line are specifically numbered as follows: "node number" + "-" + "node number" + "_" + "chord section type number", where the chord section type number is used to associate with the section parameter library, and supports the replacement of different section parameters by modifying the section type identifier.

[0020] Further,

[0021] The web member connection line is specifically named as follows: "upper chord node number" + "-" + "lower chord node number" + "_" + "web member section type number".

[0022] Further,

[0023] The packaged UDF includes a sweep UDF and a cross-section UDF. The cross-section UDF forms the center line of the cross-section contour, and then the sweep UDF is used to stretch the center line of the cross-section contour through the guide line to form a surface. Finally, the surface is thickened to realize the generation of the envelope surface model. The calling of UDF and the thickening of the surface are both implemented in batches using the EKL language.

[0024] Further,

[0025] S7 specifically:

[0026] S70. Storing the encapsulated UDF in the CATIA resource table;

[0027] S71. Use the EKL language to call the corresponding cross-section UDF to generate the cross-sections of the chord, web, and transverse connection at the corresponding locations;

[0028] S72. Then call the sweep UDF to form the surfaces of each component.

[0029] Further,

[0030] The upper chord line, lower chord line and web member line are used as input, the parameters are defined in the knowledge engineering array and the node plate and the node plate surface are generated using the EKL script.

[0031] The present invention has the beneficial effects:

[0032] 1. By using CATIA's EKL language to call bridge parameter Excel spreadsheet data, key parameters such as span length, girder height, and girder spacing are integrated into the CATIA parameter set, achieving full parametric model construction. Compared to traditional manual parameter input, this avoids duplicate entry errors, significantly shortens model preparation time, and supports the pre-configuration of various parameter types in the early stages of the design process to quickly complete multiple schemes.

[0033] 2. Based on key design parameters in the parameter set, batch generation and automatic numbering of top and bottom chord nodes are performed, along with the simultaneous automatic generation and numbering of top and bottom chord connections, web connections, and transverse connection lines. This process eliminates the need for manual point-by-point drawing, reducing repetitive operations by over 90%. This is particularly applicable to steel truss structures with multiple spans and complex node layouts, significantly improving modeling efficiency.

[0034] 3. A structured naming convention of "node number - node number - section type number" is used to directly associate component numbers for chords, webs, and other members with the node and section parameter library. By modifying the section type number in the number, different section parameters can be quickly called up, enabling visual replacement and batch updating of component sections, reducing the complexity of model maintenance.

[0035] 4. Encapsulate and store the sweep and cross-section UDFs in a CATIA resource table. Call the corresponding UDFs through a sub-geometry set to automatically generate the envelope model for the chords, webs, and transverse connections. This modular design avoids repetitive feature definition steps and supports rapid reuse and cross-project migration of model components. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Flowchart of the present invention;

[0037] Figure 2 Schematic diagram of the upper chord node and the lower chord node;

[0038] Figure 3 Schematic diagram of the upper and lower chord lines;

[0039] Figure 4 Schematic diagram of the connection line of the belly bar;

[0040] Figure 5 It is a schematic diagram of horizontal connection lines;

[0041] Figure 6 It is a schematic diagram of the steel truss frame line;

[0042] Figure 7 Schematic diagram of the first-level and second-level geometrical sets named after nodes;

[0043] Figure 8 Schematic diagram of the steel truss skeleton model. DETAILED DESCRIPTION

[0044] The present invention will be further described in detail below with reference to the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0045] For example, see Figures 1 to 8 :

[0046] A CATIA-based rapid skeleton modeling method includes an EXCEL table of bridge parameters and a packaged UDF. The EXCEL table of bridge parameters includes parameters such as span length, girder height, girder spacing, whether the girder is curved, and upper node layout parameters and lower node layout parameters. The specific steps are as follows:

[0047] S1.CATIA uses EKL language to call the parameters in the bridge parameter EXCEL table to the CATIA parameter set for standby use;

[0048] S2.CATIA reads the parameters in the parameter set and runs out the upper and lower chord nodes in batches using the EKL language, and numbers each upper and lower chord node;

[0049] S3. Connect the upper chord lines according to the order in which the upper chord nodes are batched out, and connect the lower chord lines according to the order in which the lower chord nodes are batched out, and number the upper chord lines and lower chord lines for each.

[0050] S4. Use the EKL language to obtain the numbers of all upper and lower chord nodes and store them in the second and third columns of the Excel spreadsheet to form a node table. Then, based on the layout principles of the web lines, combine the numbers of the upper and lower chord nodes to be connected in the node table and place them in the first column. Use the EKL language to call the combination numbers in the first column, generate web lines based on the combination numbers, and name them in the combination number field.

[0051] S5. Obtain the names of the two upper chord nodes or the two lower chord nodes through the EKL language pre-compiled horizontal connection layout principle, and connect them to generate horizontal connection lines;

[0052] S6. Take all upper and lower chord nodes, upper and lower chord lines, web lines, and transverse lines as input lines, and use the upper or lower chord node as the base point in the first-level geometric shape set. Find the upper chord lines, lower chord lines, web lines, and transverse lines in the input lines that satisfy the relationship with the base point defined in the EKL language, and place the base point and the upper chord lines, lower chord lines, web lines, and transverse lines that satisfy the relationship in the second-level geometric shape set named after the base point.

[0053] S7. Based on the sub-geometry set in S6, the corresponding UDF is called to generate an envelope model of the chord, web, and transverse connection to obtain a steel truss skeleton model;

[0054] S8. Modify the bridge parameter EXCEL table and re-run the script to quickly update and generate the steel truss skeleton model.

[0055] Further,

[0056] The node numbers of the upper chord nodes and the lower chord nodes are in the form of "A+i" and "E+i" respectively, where i is a number.

[0057] By using fixed-format node numbers (upper chord nodes "A+i", lower chord nodes "E+i"), a unique and ordered coordinate index is established for the model, making it easier for the program to quickly identify the spatial position and connection relationship of the nodes through numbering, realizing batch node generation, automatic connection and parametric management, avoiding manual naming confusion and improving modeling efficiency. Node numbers can also be expressed in other forms.

[0058] In one embodiment, the upper chord nodes are named "A1", "A2", "A3" ... in sequence along the span direction (e.g. Figure 2 As shown in the figure), the lower chord nodes are named "E1", "E2", "E3"..., and the numbers are directly related to the position coordinates of the nodes in the model, providing a clear logical basis for subsequent chord connections and web connections.

[0059] Further,

[0060] The upper chord line and the lower chord line are specifically numbered as follows: "node number" + "-" + "node number" + "_" + "chord section type number", where the chord section type number is used to associate with the section parameter library, and supports the replacement of different section parameters by modifying the section type identifier.

[0061] The upper and lower chord lines are numbered in the format of "node number" + "-" + "node number" + "_" + "chord section type number", which not only represents the upper or lower chord node connecting the two ends of the chord line, but also associates it with the CATIA section parameter library through the chord section type number. It supports quickly brushing and replacing the chord section by modifying the chord section type number, realizing parametric modeling and design iteration.

[0062] In one embodiment, if Figure 3 As shown, the upper chord line is numbered "A1-A2_S1", which means that the upper chord line connects the upper chord node A1 and the upper chord node A2. The section type represented by the upper chord line is S1. S1 represents a box section in the section parameter library. If you need to change the section type represented by the upper chord line, just change S1 to another chord section type number, for example, change "A1-A2_S1" to "A1-A2_S2". After the modification, the corresponding section parameters in the section parameter library will be automatically refreshed.

[0063] Further,

[0064] The naming number of the web member connection line is specifically "upper chord node number" + "-" + "lower chord node number" + "_" + "web member section type number".

[0065] The principle of web member connection is to connect the upper chord node and the lower chord node. The name is "upper chord node number-upper chord node number_web member section type number", which clearly indicates the upper chord node and lower chord node connected at both ends of the web member. Different web member cross-sectional parameters are associated with the "web member section type number". This allows engineers to change the connection method of the upper chord node and lower chord node defined in the EKL language according to design requirements to obtain a new combination number table, thereby realizing the change and generation of web member connection methods.

[0066] In one embodiment, if Figure 4 As shown in the figure, there is a web member line numbered "A2-E3_F1", where A2 represents the upper chord node, E3 represents the lower chord node, and F1 represents the web member section type number. This web member line represents the web member connecting the upper chord node A2 and the lower chord node E3, and the web member section type is F1. If you need to change the section of the web member represented by a web member line, just change the "web member section type number" in the number to another "web member section type number".

[0067] Further,

[0068] The packaged UDF includes a sweep UDF and a cross-section UDF. The cross-section UDF forms the center line of the cross-section contour, and then the sweep UDF is used to stretch the center line of the cross-section contour through the guide line to form a surface. Finally, the surface is thickened to realize the generation of the envelope surface model. The calling of UDF and the thickening of the surface are both implemented in batches using the EKL language.

[0069] UDF (User Defined Feature) is a tool that comes with CATIA to record the creation process of certain geometric features inside a part (such as surface features, solid features, etc.). It can output the final features we need.

[0070] In one embodiment, a sweep UDF takes a centerline and guide lines as input and generates a surface by sweeping. This step is then encapsulated into a UDF. As long as the corresponding edges and guide lines are available, the corresponding surface can be repeatedly generated. This function encapsulates our steps, only passing the input and then outputting the final desired result, which can reduce our repeated modeling time. The same is true for the cross-section UDF.

[0071] Further,

[0072] S7 specifically:

[0073] S70. Storing the encapsulated UDF in the CATIA resource table;

[0074] S71. Use the EKL language to call the corresponding cross-section UDF to generate the cross-sections of the chord, web, and transverse connection at the corresponding locations;

[0075] S72. Then call the sweep UDF to form the surfaces of the chord, web, and transverse connection.

[0076] In one embodiment, the organized second-level geometric graphics set named after the nodes (such as Figure 7 Node A2 in the figure is used as input. The corresponding line in the second-level geometry set is found as a guide line. The encapsulated UDF is stored in the resource table. The cross-section UDF named "JM" is called through the EKL language to generate the cross-sections of the chord, web, and transverse connection line at the corresponding positions. The sweep UDF named "SN" is called to form the surfaces of each member.

[0077] Further,

[0078] The upper chord line, lower chord line and web member line are used as input, the parameters are defined in the knowledge engineering array and the node plate and the node plate surface are generated using the EKL script.

[0079] In one embodiment, for nodes connected by two web members, such as A2-E3 and A2-E4, the EKL script reads the web member connection line, defines the nail line length and web member width in the knowledge engineering array, generates the node plate surface, and then cuts the chord surface by the plane on the large and small mileage sides of the node plate. This ensures that no matter how the chord length changes, the node plate length remains unchanged and the chord automatically matches the length change, thereby achieving automated assembly of the node plate and the member.

[0080] It will be understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present invention, and the present invention is not limited thereto. Those skilled in the art will appreciate that various modifications and improvements can be made without departing from the spirit and substance of the present invention, and such modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A CATIA-based rapid skeleton modeling method, characterized in that: It includes an EXCEL table of bridge parameters and a packaged UDF. The EXCEL table of bridge parameters includes parameters such as span length, girder height, girder spacing, whether it is a curved girder, and upper node layout parameters and lower node layout parameters. The specific steps are as follows: S1.CATIA uses EKL language to call the parameters in the bridge parameter EXCEL table to the CATIA parameter set for standby use; S2.CATIA reads the parameters in the parameter set and runs out the upper and lower chord nodes in batches using the EKL language, and numbers each upper and lower chord node; S3. Connect the upper chord lines according to the order in which the upper chord nodes are batched out, and connect the lower chord lines according to the order in which the lower chord nodes are batched out, and number the upper chord lines and lower chord lines for each. S4. Use the EKL language to obtain the numbers of all upper and lower chord nodes and store them in the second and third columns of the Excel spreadsheet to form a node table. Then, based on the layout principles of the web lines, combine the numbers of the upper and lower chord nodes to be connected in the node table and place them in the first column. Use the EKL language to call the combination numbers in the first column, generate web lines based on the combination numbers, and name them in the combination number field. S5. Obtain the names of the two upper chord nodes or the two lower chord nodes through the EKL language pre-compiled horizontal connection layout principle, and connect them to generate horizontal connection lines; S6. Take all upper and lower chord nodes, upper and lower chord lines, web lines, and transverse lines as input lines, and place them in the first-level geometry collection with the upper and lower chord nodes as base points. Find the upper and lower chord lines, web lines, and transverse lines that satisfy the relationship with the base points defined in the EKL language, and place the base points and the upper and lower chord lines, web lines, and transverse lines that satisfy the relationship in the second-level geometry collection named after the base points. S7. Based on the geometry set in the second level of S6, call the corresponding UDF to generate an envelope model of chords, webs, and transverse connections to obtain a steel truss skeleton model; S8. Modify the bridge parameter EXCEL table and re-run the script to quickly update and generate the steel truss skeleton model.

2. The CATIA-based rapid skeleton modeling method according to claim 1, characterized in that: The node numbers of the upper chord nodes and the lower chord nodes are in the form of A+i and E+i, respectively, where i is a number.

3. The CATIA-based rapid skeleton modeling method according to claim 2, characterized in that: The upper chord lines and the lower chord lines are specifically numbered as follows: node number + - + node number + _ + chord section type number, where the chord section type number is used to associate with the section parameter library, and supports the replacement of different section parameters by modifying the section type identifier.

4. The CATIA-based rapid skeleton modeling method according to claim 1, characterized in that: The web member connection line is specifically named as follows: upper chord node number + - + lower chord node number + _ + web member section type number.

5. The CATIA-based rapid skeleton modeling method according to claim 1, characterized in that: The packaged UDF includes a sweep UDF and a cross-section UDF. The cross-section UDF forms the center line of the cross-section contour, and then the sweep UDF is used to stretch the center line of the cross-section contour through the guide line to form a surface. Finally, the surface is thickened to realize the generation of the envelope surface model. The calling of UDF and the thickening of the surface are both implemented in batches using the EKL language.

6. The CATIA-based rapid skeleton modeling method according to claim 5, characterized in that: S7 specifically: S70. Storing the encapsulated UDF in the CATIA resource table; S71. Use the EKL language to call the corresponding cross-section UDF to generate the cross-sections of the chord, web, and transverse connection at the corresponding locations; S72. Then call the sweep UDF to form the surfaces of each component.

7. The CATIA-based rapid skeleton modeling method according to claim 1, characterized in that: The upper chord line, lower chord line and web member line are used as input, the parameters are defined in the knowledge engineering array and the node plate and the node plate surface are generated using the EKL script.

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