Method for automatically modeling geometric entity of three-dimensional welding seam

Abstract

The invention provides a method for automatically modeling a three-dimensional welding seam geometric entity, which comprises the following steps of: establishing a standard welding seam section library, and endowing a standard section code for each welding seam section sketch in the standard welding seam section library; the geometric features of the three-dimensional model are used for extracting part side line and plane information to recognize welding seam features; according to functions and using positions of different base materials in the product, standard names are given to the different base materials in CAD modeling software; defining a welding seam type and reasoning and calculating welding seam geometric parameters according to the standard name of the base metal; according to the welding seam type and the welding seam geometric parameters, automatically matching a standard section code corresponding to the welding seam type and the welding seam geometric parameters in a standard welding seam section library, and calling a welding seam section sketch; generating a weld track according to the identified weld features; and automatically constructing a three-dimensional welding seam geometric entity by adopting a scanning function in CAD modeling software based on the called welding seam section sketch and the welding seam track.

Description

Technical Field

[0001] The present invention relates to the field of welding, and more specifically, to a method for automatically modeling three-dimensional weld geometric entities. Background Art

[0002] In modern manufacturing, welding is a widely used metal joining process. With the continuous development of technology, the quality and performance requirements for welded structures are getting higher and higher. The traditional two-dimensional weld representation method has limitations in expressing the complexity and details of welded structures and is difficult to intuitively display the detailed shape of the weld. The three-dimensional weld geometric model is an indispensable part of current welding simulation technology and is of great significance for process planning, welding deformation prediction, welding quality control, etc. In order to better design, analyze, and optimize welded structures, it is crucial to efficiently and accurately model three-dimensional weld geometric entities.

[0003] Chinese Invention Patent published on August 30, 2024, "A Process Knowledge-Driven MBD Welding Annotation Method" (Application No.: 202410609794.5), which is based on a client connecting to a server knowledge base. According to the parent material lap joint structure, it automatically calls relevant welding joint information and processes, matches corresponding information through query statements, extracts key welding data, generates welding structure query results, and then uses a rule engine and NURBS algorithm to automatically calculate and create corresponding three-dimensional groove and three-dimensional weld entity features based on the retrieved welding information; based on the three-dimensional weld entity features, it applies a convolutional neural network and an incremental learning algorithm to match through a symbol library according to industry standards and enterprise standards, automatically selects and applies welding symbols for annotation, and generates an annotated completed state.

[0004] However, the above solution still has the following problems: 1. The generated three-dimensional weld entity features only include the groove shape, weld length, and weld position in the three-dimensional model, and cannot reflect the number of weld layers, the arrangement of weld layers, and the weld layer arrangement order; 2. The generated three-dimensional weld entity cannot meet the requirements of welding process simulation technology; 3. There are no rule constraints for continuous welds and flexible integration welding of different types of welds, and it cannot match the actual weld planning of complex factory structures, and the generated three-dimensional weld entity may not conform to actual factory welding.

[0005] In order to solve the above existing problems, people have been seeking an ideal technical solution. Summary of the Invention

[0006] The purpose of the present invention is to address the deficiencies of the prior art and thus provide a method for automatically modeling three-dimensional weld geometric entities.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a method for automatically modeling a three-dimensional weld geometric entity, comprising the following steps: Count the types of welds used in the product, use CAD modeling software to draw the weld cross-section sketches of various weld types, fillet sizes and layer arrangements, establish a standard weld cross-section library, and assign a standard section code to each weld cross-section sketch in the standard weld cross-section library; Use the geometric features of the three-dimensional model to extract the part edge and plane information to identify the weld features; For different base materials in the product according to their functions and usage positions, assign standard names to different base materials in CAD modeling software; Define the weld parameters in CAD modeling software. The weld parameters at least include the weld type and weld geometric parameters. Based on the standard name of the base material and combined with the geometric features of the three-dimensional model, infer and calculate the weld geometric parameters. The weld geometric parameters at least include the fillet size, layer arrangement, and weld connection form; Through the defined weld type and the calculated weld geometric parameters, automatically match the corresponding standard section code in the standard weld cross-section library. After successful matching, automatically retrieve the weld cross-section sketch from the standard weld cross-section library; Based on the identified weld features, automatically extract the edge curves of the weld area, plan the welding path, and determine whether disconnection processing or continuous welding is required, and then form the final weld track according to the welding joint processing rules; Based on the retrieved weld cross-section sketch and weld track, use the scanning function in CAD modeling software to automatically construct a three-dimensional weld geometric entity.

[0008] In a possible embodiment of the first aspect, using the geometric features of the three-dimensional model to extract the part edge and plane information to identify the weld features includes: extracting the part edge and plane information in the three-dimensional model through geometric features, and analyzing the distance and angle relationship between adjacent faces; combining the lap joint form between the base materials, and automatically judging whether there is a welding relationship between the base materials and the position of the weld in the generated welding relationship according to the rule engine.

[0009] In a possible embodiment of the first aspect, based on the retrieved weld cross-section sketch and weld track, using the scanning function in CAD modeling software to automatically construct a three-dimensional weld geometric entity includes: After determining the weld seam features and the weld seam trajectory, based on the previously called weld cross-section sketch, with one end of the saved weld seam trajectory as the starting point, and with the welding surfaces of the two base materials as the boundaries, the scanning function in the CAD modeling software is automatically called for the welding trajectory to scan the weld cross-section sketch into an assembly structure; each weld layer of the weld cross-section sketch is scanned into a separate part structure, and different weld layer parts are hung under the weld assembly in the form of a structure tree to form a three-dimensional weld geometric entity model.

[0010] The second aspect provides a three-dimensional weld geometric entity automatic modeling device, including: A standard weld cross-section library construction module, which is used to draw weld cross-section sketches of various weld types, fillet sizes, and layer arrangements used in the product by using CAD modeling software, establish a standard weld cross-section library, and assign a standard section code to each weld cross-section sketch in the standard weld cross-section library; A weld feature recognition module, which is used to recognize weld features by using the geometric features of the three-dimensional model to extract part edge line and plane information; A base material recognition module, which is used to assign standard names to different base materials in the product according to their functions and usage positions in the CAD modeling software; A weld parameter acquisition module, which is used to define weld parameters in the CAD modeling software. The weld parameters at least include weld type and weld geometric parameters. Based on the standard name of the base material and combined with the geometric features of the three-dimensional model, the weld geometric parameters are deduced and calculated. The weld geometric parameters at least include fillet size, layer arrangement, and weld connection form; A weld sketch matching and calling module, which is used to automatically match the corresponding standard section code in the standard weld cross-section library through the defined weld type and the calculated weld geometric parameters. After successful matching, the weld cross-section sketch is automatically retrieved from the standard weld cross-section library; A weld trajectory generation module, which is used to automatically extract the edge curve of the weld area according to the recognized weld features, plan the welding path, and judge whether disconnection processing or continuous welding is required, and then form the final weld trajectory according to the welding joint processing rules; A geometric entity construction module, which is used to automatically construct a three-dimensional weld geometric entity based on the retrieved weld cross-section sketch and the weld trajectory by using the scanning function in the CAD modeling software.

[0011] The third aspect provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in the first aspect are implemented.

[0012] The fourth aspect provides a computer program product, including a computer program. When the computer program is executed by a processor, the steps of the method described in the first aspect are implemented.

[0013] The present invention has prominent substantial features and remarkable progress compared with the prior art. Specifically, 1. For the automatic 3D weld geometric entity modeling method described in the present invention, the created weld feature expression information is more complete and comprehensive. It can not only express the overall geometric shape, but also express the geometric shape of each weld layer and each weld pass, the arrangement order of weld layers and passes, and the size of the cross-section of each weld layer and each weld pass; 2. By automatically invoking the scanning function of the CAD modeling software, the weld cross-section sketch in the server database is automatically converted into a 3D weld geometric entity model. And because the created weld features restrict the flexible integrated welding of continuous welds and different types of welds, the generated 3D weld entity can meet the requirements of welding process simulation technology for entity weld mesh division; 3. By combining the 3D design model with the production manufacturing model, the accuracy and efficiency of creating 3D weld geometric entities are greatly improved, and the integration and delivery of technical documents for design process and manufacturing can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic flow chart of the method for automatic 3D weld geometric entity modeling described in the present invention.

[0015] Figure 2 is a schematic diagram of the standard cross-section code described in the present invention.

[0016] Figure 3 is a schematic structural diagram of the 3D weld geometric entity automatic modeling device described in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The technical solutions of the present invention will be further described in detail below through specific embodiments.

[0018] Embodiment 1 This embodiment provides a method for automatic 3D weld geometric entity modeling, as Figure 1 shown, including the following steps: Count the types of welds used in the product, draw weld cross-section sketches of various weld types, fillet sizes and layer-pass arrangements using CAD modeling software, establish a standard weld cross-section library, and assign a standard cross-section code to each weld cross-section sketch in the standard weld cross-section library; Specifically, as Figure 2As shown, the standard section code includes at least the weld connection form, fillet size, welding method, weld type, and base metal strength. Among them, common weld connection forms include V-groove, K-groove, I-groove, T-groove, etc.; weld types include flat weld PA, horizontal weld PB, transverse weld PC, semi-overhead weld PD, overhead weld PE, etc.; common base metal strengths include base metal Q8 with a yield strength ≤ 690 MPa and base metal Q8 with a yield strength ≥ 890 MPa.

[0019] The following table shows examples of weld section codes corresponding to some weld types.

[0020] Weld type description Weld cross-section code Fillet weld with a fillet size of 14 mm K14_JH_PB_Q6 Groove weld with a groove depth of 18 mm and an angle of 40° V(18_40)_JH_PA_Q6 Groove weld with a groove depth of 16 mm and an angle of 45°, with an 8 mm fillet weld starting after filling V(16_45_8)_JH_PC_Q6 Extract the part edge and plane information using the geometric features of the 3D model to identify weld features.

[0021] Specifically, in one embodiment, extracting the part edge and plane information using the geometric features of the 3D model to identify weld features includes the following steps: Extract the part edge and plane information in the 3D model through geometric features, analyze the distance and angle relationship between adjacent faces, and combine the lap joint form between base metals to automatically determine whether there is a welding relationship between base metals and the position of the weld in the generated welding relationship.

[0022] For different base metals in the product according to their functions and usage positions, assign standard names to different base metals in the CAD modeling software. Specifically, in the CAD modeling software, match the different part ID numbers and names in the part list BOM according to the standard name definition table, and assign standard names to different parts based on the matching results, that is, realize assigning respective standard names to different base metals.

[0023] Define the weld parameters in the CAD modeling software. The weld parameters include at least the weld type and weld geometric parameters. Based on the standard name of the base metal and combined with the geometric features of the 3D model, infer and calculate the weld geometric parameters; the weld geometric parameters include at least the fillet size, layer arrangement, and weld connection form.

[0024] Specifically, when inferring and calculating the weld geometric parameters, it is necessary to combine the design specifications and industry standards.

[0025] Automatically match the corresponding standard section code in the standard weld section library through the defined weld type and the calculated weld geometric parameters. After successful matching, automatically retrieve the weld section sketch from the standard weld section library.

[0026] Based on the identified weld features, automatically extract the edge curve of the weld area, plan the welding path, and determine whether disconnection processing or continuous welding is required, and then form the final weld track according to the welding joint processing rules.

[0027] It should be noted that when determining whether disconnection processing or continuous welding is required, the welding path needs to be segmented and merged in combination with the welding feature operation rule table. Specifically, the welding feature operation rule table is set with operations corresponding to different weld lengths, weld spacings, weld inclinations, weld rotations, fillet sizes, and weld structures.

[0028] Based on the retrieved weld cross-section sketch and weld trajectory, the scanning function in CAD modeling software is used to automatically construct a three-dimensional weld geometric entity.

[0029] In a possible embodiment, based on the retrieved weld cross-section sketch and weld trajectory, the scanning function in CAD modeling software is used to automatically construct a three-dimensional weld geometric entity, including: After determining the weld features and weld trajectory, based on the previously retrieved weld cross-section sketch, with one end of the saved weld trajectory as the starting point, and taking the welding surfaces of the two base materials as the boundaries, the scanning function in CAD modeling software is automatically called for the welding trajectory to scan the weld cross-section sketch into an assembly structure; each weld layer of the weld cross-section sketch is scanned into a separate part structure, and different weld layer parts are hung under the weld assembly in the form of a structure tree to form a three-dimensional weld geometric entity model.

[0030] Specifically, since the weld cross-section sketch is composed of the cross-section sketches of each layer and each pass, and the cross-section sketches of each layer and each pass are named in the form of Sketch 1, Sketch 2 according to the welding sequence. Similarly, the weld layer parts generated by scanning will be named PRT1, PRT2 according to the sketch sequence, so that the welding sequence of each layer and each pass of the weld can be intuitively seen.

[0031] It can be seen that the automatic modeling method of the three-dimensional weld geometric entity described in this embodiment creates more complete and comprehensive weld feature expression information, which can not only express the overall geometric shape, but also express the weld geometric shape, weld layer arrangement sequence and the size of each weld cross-section of each layer and each pass; in addition, due to the above content restricting the flexible integrated welding of continuous welds and different types of welds, the generated three-dimensional weld entity can meet the requirements of the welding process simulation technology for the entity weld mesh division; Finally, this embodiment combines the three-dimensional design model with the production manufacturing model, greatly improving the accuracy and efficiency of creating the three-dimensional weld geometric entity, and enabling the integrated delivery of technical data for design process and manufacturing.

[0032] Embodiment 2 This embodiment provides an automatic modeling device for a three-dimensional weld geometric entity, as Figure 3 shown, including: The standard weld cross-section library construction module is used to draw the weld cross-section sketches of various weld types, fillet sizes, and layer arrangements used in the product using CAD modeling software, establish a standard weld cross-section library, and assign a standard cross-section code to each weld cross-section sketch in the standard weld cross-section library. The standard cross-section code includes at least the weld connection form, fillet size, welding method, weld type, and base material strength.

[0033] The weld feature recognition module is used to recognize weld features by extracting part edge and plane information using the geometric features of the 3D model; specifically, the weld feature recognition module extracts part edge and plane information using the geometric features of the 3D model to recognize weld features, including: extracting part edge and plane information in the 3D model through geometric features, analyzing the distance and angle relationships between adjacent faces; combining the lap form between base materials, and automatically judging whether there is a welding relationship between base materials and the position of the weld in the generated welding relationship according to the rule engine.

[0034] The base material recognition module is used to assign standard names to different base materials in the product according to their functions and usage positions in CAD modeling software.

[0035] The weld parameter acquisition module is used to define weld parameters in CAD modeling software. The weld parameters include at least weld type and weld geometric parameters. Based on the standard name of the base material and combined with the geometric features of the 3D model, the weld geometric parameters are deduced and calculated; the weld geometric parameters include at least fillet size, layer arrangement, and weld connection form.

[0036] The weld sketch matching and calling module is used to automatically match the corresponding standard cross-section code in the standard weld cross-section library through the defined weld type and the calculated weld geometric parameters, and automatically retrieve the weld cross-section sketch from the standard weld cross-section library after successful matching.

[0037] The weld path generation module is used to automatically extract the edge curve of the weld area, plan the welding path according to the recognized weld features, judge whether disconnection processing or continuous welding is required, and then form the final weld path according to the welding joint processing rules.

[0038] The geometric entity construction module is used to automatically construct a 3D weld geometric entity using the scan function in CAD modeling software based on the retrieved weld cross-section sketch and weld path.

[0039] Specifically, the geometric entity construction module automatically constructs a 3D weld geometric entity using the scan function in CAD modeling software based on the retrieved weld cross-section sketch and weld path, including: After determining the weld characteristics and the weld path, based on the previously called weld cross-section sketch, starting from one end of the saved weld path, and taking the welding surfaces of the two base materials as the boundaries, automatically call the sweep function in the CAD modeling software for the welding path to sweep the weld cross-section sketch into an assembly structure; each weld layer of the weld cross-section sketch is swept into a separate part structure, and different weld layer parts are attached under the weld assembly in the form of a structure tree to form a three-dimensional weld geometric entity model.

[0040] Embodiment 3 This embodiment provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in Embodiment 1 are implemented.

[0041] Embodiment 4 This embodiment provides a computer program product, including a computer program. When the computer program is executed by a processor, the steps of the method described in Embodiment 1 are implemented.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that it is still possible to modify the specific implementation manners of the present invention or perform equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A method for automatically modeling a three-dimensional weld geometric entity, characterized in that, It includes the following steps: Count the types of welds used in the product, use CAD modeling software to draw the weld cross-section sketches of various weld types, fillet sizes and layer arrangements, establish a standard weld cross-section library, and assign a standard section code to each weld cross-section sketch in the standard weld cross-section library; Use the geometric features of the 3D model to extract part edge and plane information to identify weld features; For different base materials in the product according to their functions and usage positions, assign standard names to different base materials in CAD modeling software; Define weld parameters in CAD modeling software, where the weld parameters at least include weld type and weld geometric parameters, and infer and calculate the weld geometric parameters based on the standard name of the base material and combined with the geometric features of the 3D model; the weld geometric parameters at least include fillet size, layer arrangement, and weld connection form; Automatically match the corresponding standard section code in the standard weld cross-section library through the defined weld type and calculated weld geometric parameters. After successful matching, automatically retrieve the weld cross-section sketch from the standard weld cross-section library; Based on the identified weld features, automatically extract the edge curve of the weld area, plan the welding path, and determine whether disconnection processing or continuous welding is required, and then form the final weld track according to the welding joint processing rules; Based on the retrieved weld cross-section sketch and weld track, use the scanning function in CAD modeling software to automatically construct a 3D weld geometric entity.

2. The method for automatically modeling a three-dimensional weld geometry entity according to claim 1, characterized in that Use the geometric features of the 3D model to extract part edge and plane information to identify weld features, including: extracting part edge and plane information in the 3D model through geometric features, analyzing the distance and angle relationship between adjacent faces; combining the lap joint form between base materials, and automatically judging whether there is a welding relationship between base materials and the position of the weld in the generated welding relationship according to the rule engine.

3. A method for automatically modeling a three-dimensional weld geometric entity according to claim 2, characterized in that, Based on the retrieved weld cross-section sketch and weld track, use the scanning function in CAD modeling software to automatically construct a 3D weld geometric entity, including: After determining the weld features and weld track, based on the previously retrieved weld cross-section sketch, taking one end of the saved weld track as the starting point, and taking the welding surface of the two base materials as the boundary, automatically call the scanning function in CAD modeling software for this welding track to scan the weld cross-section sketch into an assembly structure; scan each weld layer of the weld cross-section sketch into a separate part structure, and hang different weld layer parts under the weld assembly in the form of a structure tree to form a 3D weld geometric entity model.

4. A method for automatically modeling a three-dimensional weld geometric entity according to claim 1 or 2 or 3, characterized in that, The standard section code at least includes weld connection form, fillet size, welding method, weld type, and base material strength.

5. An automatic modeling device for three-dimensional weld geometric entities, characterized in that, It includes: A standard weld cross-section library construction module for using CAD modeling software to draw the weld cross-section sketches of various weld types, fillet sizes and layer arrangements used in the product, establishing a standard weld cross-section library, and assigning a standard section code to each weld cross-section sketch in the standard weld cross-section library; A weld feature identification module for using the geometric features of the 3D model to extract part edge and plane information to identify weld features; The base material identification module is used to assign standard names to different base materials in a product according to their functions and usage locations in CAD modeling software; The weld parameter acquisition module is used to define weld parameters in CAD modeling software. The weld parameters at least include weld type and weld geometric parameters. Based on the standard names of the base materials and combined with the geometric features of the 3D model, the weld geometric parameters are deduced and calculated. The weld geometric parameters at least include fillet size, layer arrangement, and weld connection form; The weld sketch matching and calling module is used to automatically match the corresponding standard section code in the standard weld section library through the defined weld type and the calculated weld geometric parameters. After successful matching, the weld section sketch is automatically retrieved from the standard weld section library; The weld path generation module is used to automatically extract the edge curve of the weld area based on the identified weld features, plan the welding path, and determine whether disconnection processing or continuous welding is required. Then, the final weld path is formed according to the welding joint processing rules; The geometric entity construction module is used to automatically construct a 3D weld geometric entity based on the retrieved weld section sketch and the weld path by using the sweep function in CAD modeling software.

6. The automatic 3D weld geometry entity modeling device according to claim 5, characterized in that The weld feature recognition module uses the geometric features of the 3D model to extract part edge and plane information to recognize weld features, including: extracting part edge and plane information in the 3D model through geometric features, analyzing the distance and angle relationship between adjacent faces; combining the lap joint form between base materials, and automatically judging whether there is a welding relationship between base materials and the position of the weld in the generated welding relationship according to the rule engine.

7. An automatic 3D weld geometry entity modeling device according to claim 5 or 6, characterized in that The geometric entity construction module automatically constructs a 3D weld geometric entity based on the retrieved weld section sketch and the weld path by using the sweep function in CAD modeling software, including: After determining the weld features and the weld path, based on the previously retrieved weld section sketch, with one end of the saved weld path as the starting point, and taking the welding surface of the two base materials as the boundary, the sweep function in CAD modeling software is automatically called for this welding path to scan the weld section sketch into an assembly structure; each weld layer of the weld section sketch is scanned into a separate part structure, and different weld layer parts are hung under the weld assembly in the form of a structure tree to form a 3D weld geometric entity model.

8. The automatic 3D weld seam geometric entity modeling device according to claim 7, characterized in that The standard section code at least includes weld connection form, fillet size, welding method, weld type, and base material strength.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method described in any one of claims 1 to 4.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method described in any one of claims 1 to 4.

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