Finite element automatic generation method, device and equipment for vehicle body connecting part
By automatically identifying and generating the envelope space and rigidity elements of fasteners, the problem of time-consuming manual creation of fastener elements is solved, thus improving the efficiency of vehicle body simulation.
Patent Information
- Application Number
- CN202510935653.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-08
- Publication Date
- 2025-10-21
AI Technical Summary
In existing technologies, the process of manually creating equivalent elements for fasteners used in FDS and SPR by simulation engineers is time-consuming and seriously affects the efficiency of vehicle body simulation.
By automatically traversing the envelope surface of the fastener, identifying the target end face, generating the envelope space, and automatically generating rigid elements based on the physical nodes of the connected parts within the envelope space, the automatic connection of fasteners is achieved.
It significantly shortens the time for batch processing of FDS or SPR connections in finite element modeling of vehicle bodies, reduces manpower input, and improves simulation efficiency.
Smart Images
Figure CN120822376A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of finite element modeling, and in particular to a method, device and equipment for automatically generating finite elements of vehicle body connection parts. Background Art
[0002] To adapt to the lightweight development of automobiles, body structures that use a mixture of multiple materials such as aluminum alloy, magnesium alloy, and carbon fiber composite materials are becoming increasingly popular. Traditional resistance spot welding processes are difficult to adapt to the connection requirements of these materials. Therefore, flow drill screw (FDS) and self-piercing riveting (SPR) are commonly used in body connection parts.
[0003] In related technologies, simulation engineers generally manually screen fasteners used for FDS and SPR during the finite element modeling process and create rigid units to replace the fasteners. This process is time-consuming and seriously affects the efficiency of vehicle body simulation. Summary of the Invention
[0004] The present application provides a method, device and equipment for automatically generating finite elements of vehicle body connection parts, which solves the problem of long time and low efficiency in the current finite element modeling process in which simulation engineers manually create equivalent units for fasteners used in FDS and SPR. It can batch identify the envelope surface and connection direction of fasteners, thereby automatically generating the corresponding envelope space and corresponding rigid units, greatly shortening the modeling time and improving the efficiency of simulation work.
[0005] In order to achieve the above objectives, the main technical solutions adopted in this application include:
[0006] In a first aspect, an embodiment of the present application provides a method for automatically generating finite elements of a vehicle body connection portion, wherein the connection portion adopts an FDS or SPR connection method and the vehicle body is connected by fasteners. The method includes:
[0007] Traversing each envelope surface of each fastener in the vehicle body to identify a target end surface in the envelope surface during the traversal process, and determining a connection direction of the fastener according to the target end surface;
[0008] Acquiring outer contour parameters of the fastener, and generating an envelope space of the fastener according to the connection direction and the outer contour parameters;
[0009] A connected part corresponding to the fastener is determined, and a rigid unit corresponding to the fastener is automatically generated according to each entity node of the connected part in the envelope space, so as to perform finite element modeling of the FDS or SPR connection of the vehicle body through the rigid unit.
[0010] The automatic finite element generation method provided in this embodiment automatically traverses the envelope surface of the fastener to determine the connection direction and ensure the accurate generation of the envelope space. It then automatically generates rigid elements based on the physical nodes of the connected parts within the envelope space. This avoids the tedious operation of simulation engineers manually completing FDS or SPR connections one by one, significantly shortens the time for batch processing FDS or SPR connections in vehicle body finite element modeling, reduces manpower investment, and greatly improves simulation work efficiency.
[0011] Optionally, in some embodiments of the present application, traversing each envelope surface of each fastener in the vehicle body to identify a target end face in the envelope surface during the traversal process includes:
[0012] Traversing each of the envelope surfaces based on an index corresponding to each of the envelope surfaces, and obtaining a first geometric area of each of the envelope surfaces based on a geometric feature of the fastener during the traversal process;
[0013] A target end surface in the envelope surface is identified based on the first geometric area.
[0014] The embodiment of the present application traverses the envelope surface through indexing and obtains the first geometric area of the envelope surface during the traversal process, and then automatically identifies the target end face based on the first geometric area, providing an accurate basis for determining the subsequent fastener connection direction, effectively avoiding possible deviations in manual identification, and thus more efficiently and accurately realizing finite element modeling of the vehicle body connection parts.
[0015] Optionally, in some embodiments of the present application, identifying the target end face in the envelope surface according to the first geometric area includes:
[0016] A reference area is determined, the first geometric area is matched with the reference area, and the target end face is determined in the envelope surface according to the matching result.
[0017] The embodiment of the present application realizes automatic identification of the target end face by setting a reference area and matching it with the first geometric area. More specifically, the target end face has a definite relationship with the connection direction of the fastener, so that the connection direction can be accurately and reliably determined through the target end face, which is conducive to improving the accuracy of subsequent modeling.
[0018] Optionally, in some embodiments of the present application, the process of determining the reference area includes:
[0019] A second geometric area of a designated end face of the fastener is determined according to standard geometric parameters of the fastener, and the second geometric area is used as the reference area.
[0020] The embodiment of the present application uses the second geometric area of the specified end face of the fastener as the reference area, and uses the reference area as a benchmark to achieve automatic identification of the target end face, which is conducive to more accurate determination of the connection direction of the fastener and provides an accurate basis for the subsequent generation of accurate envelope space and correct generation of rigid units.
[0021] Optionally, in some embodiments of the present application, determining the connection direction of the fastener according to the target end face includes:
[0022] Obtaining the outer edge line of the target end face, and extracting any arc line in the outer edge line;
[0023] A center point corresponding to the arc line is determined, and a normal vector corresponding to the target end face is generated at the position of the center point, so as to determine the connection direction of the fastener according to the normal vector.
[0024] The embodiment of the present application determines the normal vector based on the center point of any arc line in the outer edge line of the target end face. The normal vector can accurately represent the connection direction perpendicular to the target end face, effectively avoiding modeling errors caused by inaccurate determination of the connection direction, thereby helping to improve modeling accuracy.
[0025] Optionally, in some embodiments of the present application, obtaining outer contour parameters of the fastener and generating an envelope space of the fastener according to the connection direction and the outer contour parameters includes:
[0026] Determining maximum dimension data of the fastener according to standard geometric parameters of the fastener, and determining the outer contour parameters according to the maximum dimension data; wherein the outer contour parameters are greater than or equal to the maximum dimension data;
[0027] An envelope coordinate system is generated according to the connection direction, and the envelope space is generated in the envelope coordinate system according to the outer contour parameters.
[0028] The embodiment of the present application generates an envelope coordinate system based on the connection direction, so that the generation of the envelope space has a clear direction reference, and determines the boundary of the envelope space according to the maximum size data of the fastener, thereby accurately generating an envelope space that can completely cover the fastener.
[0029] Optionally, in some embodiments of the present application, automatically generating a rigid unit corresponding to the fastener according to each physical node of the connected component in the envelope space includes:
[0030] Obtaining the three-dimensional coordinates of each of the physical nodes in the envelope space, and determining the three-dimensional distribution center point corresponding to all the physical nodes according to the three-dimensional coordinates, so as to use the three-dimensional distribution center point as the main node of the rigid unit;
[0031] All the entity nodes are used as a plurality of slave nodes of the rigid unit, and a plurality of the slave nodes are respectively bound to the master node, so as to generate the rigid unit according to the binding results.
[0032] In the embodiment of the present application, the entity nodes of the connected parts are divided into envelope spaces, and rigid motion constraints are imposed on these entity nodes and the fasteners. Then, the master nodes and slave nodes of the rigid units are determined according to the distribution of these entity nodes in the envelope space, and the rigid units corresponding to the fasteners are automatically generated based on the master nodes and slave nodes, thereby greatly improving the efficiency of rigid unit generation.
[0033] Optionally, in some embodiments of the present application, each envelope surface of the fastener is determined by:
[0034] obtaining geometric characteristics of the fastener;
[0035] The envelope surfaces of the fasteners are determined according to geometric features of the fasteners.
[0036] In a second aspect, an embodiment of the present application provides a finite element automatic generation device for a vehicle body connection portion, wherein the connection portion adopts an FDS or SPR connection method and is connected to the vehicle body via fasteners, the device comprising:
[0037] a direction determination module, configured to traverse each envelope surface of each fastener in the vehicle body, identify a target end surface in the envelope surface during the traversal process, and determine a connection direction of the fastener based on the target end surface;
[0038] an envelope generating module, configured to obtain outer contour parameters of the fastener and generate an envelope space of the fastener according to the connection direction and the outer contour parameters;
[0039] A rigid unit generation module is used to determine the connected part corresponding to the fastener, and automatically generate a rigid unit corresponding to the fastener based on each entity node of the connected part in the envelope space, so as to perform finite element modeling of the FDS or SPR connection of the vehicle body through the rigid unit.
[0040] The finite element automatic generation device proposed in the embodiment of the present application ensures the generation of accurate envelope space by automatically traversing the envelope surface to determine the connection direction, automatically generating the envelope space, and automatically generating rigid units based on the nodes of the connected parts. It also automatically generates rigid units based on the physical nodes of the connected parts in the envelope space, avoiding the tedious operation of simulation engineers manually completing FDS or SPR connections one by one, greatly shortening the time for batch processing of FDS or SPR connections in vehicle body finite element modeling, reducing manpower investment, and greatly improving simulation work efficiency.
[0041] In a third aspect, an embodiment of the present application provides a computer device, including:
[0042] A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the above-mentioned finite element automatic generation method for the vehicle body connection parts by executing the computer instructions. BRIEF DESCRIPTION OF THE DRAWINGS
[0043] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0044] Figure 1 The process of an embodiment of a finite element automatic generation method for a vehicle body connection part proposed in this application Figure 1 ;
[0045] Figure 2 Schematic diagram of the envelope surface of the screw in the embodiment of the present application;
[0046] Figure 3 The process of the finite element automatic generation method of the vehicle body connection part proposed in this application in one embodiment Figure 2 ;
[0047] Figure 4 This is a schematic diagram of the process of envelope surface traversal in one embodiment of the present application;
[0048] Figure 5 The process of the finite element automatic generation method of the vehicle body connection part proposed in this application in one embodiment Figure 3 ;
[0049] Figure 6 Schematic diagram of generating the normal vector corresponding to the screw in the embodiment of the present application;
[0050] Figure 7 The process of the finite element automatic generation method of the vehicle body connection part proposed in this application in one embodiment Figure 4 ;
[0051] Figure 8 Schematic diagram of the envelope space of the screw in the embodiment of the present application;
[0052] Figure 9 The process of the finite element automatic generation method of the vehicle body connection part proposed in this application in one embodiment Figure 5 ;
[0053] Figure 10 This is a schematic diagram of generating a rigid unit corresponding to a screw in an embodiment of the present application;
[0054] Figure 11 This is a schematic diagram of the structure of a finite element automatic generation device for a vehicle body connection part proposed in an embodiment of the present application;
[0055] Figure 12 A schematic diagram of the structure of a computer device proposed in an embodiment of the present application. DETAILED DESCRIPTION
[0056] To make the purpose, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of this application.
[0057] To adapt to the lightweight development of automobiles, body structures that use a mixture of multiple materials such as aluminum alloy, magnesium alloy, and carbon fiber composite materials are becoming increasingly popular. Traditional resistance spot welding processes are difficult to adapt to the connection requirements of these materials. Therefore, flow drill screw (FDS) and self-piercing riveting (SPR) are commonly used in body connection parts.
[0058] The FDS joining method involves a riveting process in which a fastener rotates at high speed under the action of a riveting machine while simultaneously pressing down into the connected parts, locking them after tapping. The SPR joining method is a cold forming process that creates a secure interlock between the rivet and the sheet metal. The rivet penetrates the upper sheet metal directly under the pressure of a hydraulic press, while the lower sheet metal plastically deforms under the action of the die, forming a mechanical interlocking structure. Both processes can connect dissimilar materials and offer the advantage of a high level of process integration.
[0059] In some application scenarios of related technologies, simulation engineers generally manually screen fasteners used for FDS and SPR and create rigid units to replace the fasteners during the finite element modeling process. It generally takes 1 to 2 minutes to manually create a rigid unit for a fastener. In the finite element model of the entire vehicle body, the total number of fasteners using FDS and SPR connection methods can be as high as 1,000. The work of a simulation engineer takes up to 30 hours, which seriously affects the efficiency of the vehicle body simulation and has high labor costs.
[0060] In addition, the process of manually identifying, screening, adjusting fasteners and creating connection units involves a large amount of repetitive work, which is prone to modeling errors. For example, in the process of creating batch FDS and SPR connections, components may be missed or incorrectly selected, and the incorrect adjustment of the perspective may cause the rigid unit to not conform to the actual working conditions, thereby affecting the accuracy of finite element modeling and simulation.
[0061] According to an embodiment of the present application, an embodiment of a method for automatically generating finite elements of vehicle body connection parts is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.
[0062] In this embodiment, a method for automatically generating finite elements for vehicle body connection parts is provided, which can be used in finite element modeling software such as HyperWorks and ANSA. More specifically, the embodiment of the present application can call the API command of HyperMesh software based on the tcl (tool command language) language to implement the automatic finite element generation method. The tcl language is a scripting language used to describe scripts, simulation network environments and parameter settings. HyperMesh software is a CAE pre-processing tool that provides a rich set of API (Application Programming Interface) commands, allowing users to extend its functionality through externally programmed scripts.
[0063] Figure 1 This is a flow chart of the finite element automatic generation method in one embodiment of the present application. In the finite element automatic generation method proposed in the embodiment of the present application, the above-mentioned connection parts adopt the connection method of FDS or SPR, and are connected to the body by fasteners, such as Figure 1 As shown, the process includes the following steps:
[0064] Step S1 , traversing each envelope surface of each fastener in the vehicle body, identifying a target end surface in the envelope surface during the traversal process, and determining a connection direction of the fastener according to the target end surface.
[0065] In an embodiment of the present application, the above-mentioned fasteners include at least one of screws and rivets, wherein screws are used when implementing the FDS connection mode, and rivets are used when implementing the SPR connection mode.
[0066] Specifically, for each fastener used in the vehicle body, each of its envelope surfaces must be traversed. In HyperMesh, the Tcl command *createmarkpanel solids is called to select the fastener's geometric entity solid to obtain the fastener index ID. The Tcl command hm_getvalue solidsid=() dataname=surfaces is then called to obtain the index of each of the fastener's envelope surfaces, outputting an index list S = [s1,s2,s3,s4,s5,...si]. It should be noted that the index list S above is only an example of how to sort the envelope surfaces and does not limit the order of the envelope surface indices.
[0067] In the embodiment of the present application, taking the sleeve type welding screw as an example, the envelope surface corresponding to each index is as follows: Figure 2 As shown in the figure, the target end face is identified among all envelope surfaces during the traversal process. Specifically, the fastener connection direction is perpendicular to the target end face. Because the connection or penetration direction of fasteners such as screws is not fixed, and the fastener connection direction is closely related to the mechanical transmission and structural stability of the connection part, determining the accurate connection direction is beneficial to improving the accuracy of finite element modeling.
[0068] Step S3: Obtain outer contour parameters of the fastener, and generate an envelope space of the fastener according to the connection direction and the outer contour parameters.
[0069] In the embodiment of the present application, the outer contour parameters of the fastener characterize the geometric dimension information of the fastener in space, so the outer contour parameters determine the specific size and shape of the envelope space. Specifically, based on the spatial orientation determined by the connection direction, according to the value of the outer contour parameters, the spatial range defined in the three-dimensional space can completely cover the envelope space (block) of the fastener. In the HyperMesh software, the envelope space is created by calling the command *createblockwithsystem in the tcl language. The envelope space not only accurately reflects the geometric shape and size of the fastener itself, but also takes into account its connection direction in the vehicle body structure, thereby laying a solid foundation for the subsequent determination of the interaction relationship between the connected parts and the fastener, the generation of accurate rigid units, and the construction of accurate finite element models.
[0070] Step S5 , determining the connected part corresponding to the fastener, and automatically generating the rigid unit corresponding to the fastener according to each entity node of the connected part in the envelope space, so as to perform finite element modeling of the FDS or SPR connection of the vehicle body through the rigid unit.
[0071] In the embodiment of the present application, the rigid unit is mainly used to simulate the completely rigid or nearly rigid connection behavior between components. It can automatically capture the finite element mesh of the connected parts and force the displacement and rotation between multiple nodes captured in the finite element mesh to remain consistent, thereby realizing the simulation of the rigid characteristics such as the transmission force and constrained displacement generated by the connected parts under the action of the fasteners.
[0072] Specifically, in the HyperMesh software, the command *createmark nodes1 "byblock" is called in the Tcl language to obtain all the above-mentioned entity nodes, and the command *rigidlinkinodecalandcreate is called to generate the rbe2 rigid element based on the node ID of the above-mentioned entity nodes, thereby completing the creation of the FDS connection.
[0073] Therefore, the finite element automatic generation method provided in this embodiment determines the connection direction by automatically traversing the envelope surface of the fastener and ensures the accurate generation of the envelope space, and then automatically generates rigid units based on the physical nodes of the connected parts in the envelope space, avoiding the tedious operation of simulation engineers manually completing FDS or SPR connections one by one, greatly shortening the time for batch processing of FDS or SPR connections in vehicle body finite element modeling, reducing manpower investment, and greatly improving simulation work efficiency.
[0074] Figure 3 The process of the finite element automatic generation method in one embodiment of the present application is shown Figure 2 ,like Figure 3 As shown, the above S1 may include the following steps:
[0075] Step S13: traverse each envelope surface based on the index corresponding to each envelope surface, and obtain a first geometric area of each envelope surface based on the geometric characteristics of the fastener during the traversal process.
[0076] In the embodiment of the present application, before executing the above step S13, each envelope surface of the fastener is first determined by the following method: obtaining geometric features of the fastener, and determining each envelope surface of the fastener according to the geometric features of the fastener.
[0077] Specifically, the relevant data of the geometric features of the fasteners are imported into the HyperMesh software. Through specific mathematical algorithms or modeling rules, these envelope surfaces can be accurately constructed in three-dimensional space based on the geometric features. For example, if the fastener is a screw, its geometric features include the diameter, length, thread size, and nut size of the upper end face of the screw. For another example, if the fastener is a rivet, its geometric features include the shank diameter, shank length, nut diameter, and nut thickness of the rivet. In HyperMesh software, the above geometric features can be used to generate Figure 2The various envelope surfaces of the screw are shown.
[0078] Step S15: identifying the target end face in the envelope surface according to the first geometric area.
[0079] Therefore, the embodiment of the present application traverses the envelope surface through indexing and obtains the first geometric area of each envelope surface during the traversal process, and then automatically identifies the target end face based on the first geometric area, providing an accurate basis for determining the subsequent fastener connection direction, effectively avoiding the deviation that may occur in manual identification, and thus realizing the finite element modeling of the vehicle body connection parts more efficiently and accurately.
[0080] The above S15 further includes: determining a reference area, matching the first geometric area with the reference area, and determining a target end face in the envelope surface according to the matching result.
[0081] The embodiment of the present application realizes automatic identification of the target end face by setting a reference area and matching it with the first geometric area. More specifically, the target end face has a definite relationship with the connection direction of the fastener, so that the connection direction can be accurately and reliably determined through the target end face, which is conducive to improving the accuracy of subsequent modeling.
[0082] The process of determining the reference area includes: determining a second geometric area of a designated end face of the fastener according to geometric parameters of a standard part of the fastener, and using the second geometric area as the reference area.
[0083] Specifically, taking a screw as an example, the designated end face is the upper end face of the screw. Since the screw is a standard part, once its size specifications are determined, the area of the upper end face can be determined as the second geometric area a based on the geometric parameters of the standard part corresponding to the size specifications, that is, the reference area value is a.
[0084] The embodiment of the present application uses the second geometric area of the specified end face of the fastener as the reference area, and uses the reference area as a benchmark to achieve automatic identification of the target end face, which is conducive to more accurate determination of the connection direction of the fastener and provides an accurate basis for the subsequent generation of accurate envelope space and correct generation of rigid units.
[0085] Figure 4 The following is a schematic diagram of the envelope surface traversal process using a screw as an example, including the following steps:
[0086] Step S11, obtaining the screw geometry ID. In HyperMesh, the Tcl language command *createmarkpanelsolids is called to select the geometric entity (solid) of the fastener, thereby obtaining the geometry ID of a single screw.
[0087] Step S12: Obtain the ID list S of all the screw envelope surfaces and the length of the list. Specifically, the index list S = [s1, s2, s3, s4, s5] of the envelope surface is obtained by calling the command hm_getvalue solids id = () dataname = surfaces in the Tcl language.
[0088] Step S13: Traverse each envelope surface based on its corresponding index. During the traversal, the first geometric area of each envelope surface is obtained based on the geometric characteristics of the screw. Specifically, a reference area value a is set, index i = 0, and the first geometric area ai of each envelope surface is obtained. Specifically, the first geometric area ai of the envelope surface si is obtained by calling the Tcl language command hm_getareaofsurface surf.
[0089] Step S14, determine whether the index i is less than the list length, if it is less than the list length, execute step S15, otherwise, end the loop.
[0090] Step S15: Match the first geometric area with the reference area, and determine the target end face in the envelope surface based on the matching result. Specifically, if the matching result shows that the first geometric area ai is equal to the reference area a, then execute step S16; otherwise, execute step S17.
[0091] Step S16: outputting the envelope surface index, that is, determining whether the envelope surface corresponding to the current index is the target end surface.
[0092] Step S17 , setting i=i+1, that is, repeating the judgment of step S15 for the envelope surface corresponding to the next index i+1.
[0093] Figure 5 The process of the finite element automatic generation method in one embodiment of the present application is shown Figure 3 ,like Figure 5 As shown, the above S1 may further include the following steps:
[0094] Step S18, obtaining the outer edge line of the target end face, and extracting any arc line in the outer edge line;
[0095] Step S19: determining the center point of the arc line, and generating a normal vector corresponding to the target end face at the position of the center point, so as to determine the connection direction of the fastener according to the normal vector.
[0096] In the embodiments of this application, Figure 6The normal vector vector generated corresponding to a screw is shown. The target end face of fasteners such as screws and rivets is circular, so the embodiment of the present application extracts any arc line in the outer edge line, and determines the position of the normal vector based on the center point of the arc line, and the normal vector is perpendicular to the target end face. Taking a screw as an example, the center point is in the screw direction of the screw, and the screw direction determines the direction of the screw passing through the connected part. It can be seen that the normal vector generated by the above steps can accurately characterize the direction of the screw passing, that is, the above connection direction. And the accurate identification of the connection direction is ensured by the above steps S18 and S19, which is conducive to ensuring the accurate generation of subsequent rigid units.
[0097] Specifically, in HyperMesh, you can use the Tcl command hm_getsurfaceedges to obtain the IDs of the two semicircular arcs of the target end face, forming a list L = [l1, l2]. Then, use the Tcl command *createbestcirclecenternodelines to generate the center point of arc l1 or l2 and record it as Pc. Then, use the Tcl command *nodesassociatetogeometry to associate the center point Pc with the target end face. Then, use the Tcl command hm_getsurfacenormal node to obtain the normal vector V = [Vx, Vy, Vz] of the target end face generated at the center point Pc.
[0098] Therefore, the embodiment of the present application determines the normal vector based on the center point of any arc line in the outer edge line of the target end face. The normal vector can accurately represent the connection direction perpendicular to the target end face, effectively avoiding modeling errors caused by inaccurate determination of the connection direction, thereby helping to improve modeling accuracy.
[0099] Figure 7 The process of the finite element automatic generation method in one embodiment of the present application is shown Figure 4 ,like Figure 7 As shown, the above S3 may include the following steps:
[0100] Step S31 , determining maximum dimension data of the fastener according to standard geometric parameters of the fastener, and determining outer contour parameters according to the maximum dimension data; wherein the outer contour parameters are greater than or equal to the maximum dimension data.
[0101] Step S33: generating an envelope coordinate system according to the connection direction, and generating an envelope space in the envelope coordinate system according to the outer contour parameters.
[0102] Specifically, the standard geometric parameters of fasteners characterize the shape and size of the fasteners. By analyzing and comparing these standard geometric parameters, the maximum values in various dimensions (such as length, width, and height) are found. These maximum values are combined to form the maximum size data of the fastener. Taking a screw as an example, its standard geometric parameters characterize the diameter, length, upper end face diameter, etc. of the screw. From the shape of the screw, it can be known that the upper end face diameter and the screw length are the maximum size data of the screw. Therefore, the upper end face diameter can be increased by a certain ratio, such as 10%, as the outer contour parameter corresponding to the length and width of the envelope space, and the screw length can be increased by a certain ratio, such as 10%, as the outer contour parameter corresponding to the height of the envelope space. This ensures that the outer contour parameters are greater than the maximum size data, and then the envelope space is generated by calling the command *createblockwithsystem in the Tcl language. Figure 8 The envelope of the screw is shown, as Figure 8 As shown, the embodiment of the present application determines the outer contour parameters according to the upper end face diameter of the screw, and uses the outer contour parameters greater than the upper end face diameter as the length and width of the envelope space, and uses the outer contour parameters greater than the screw length as the height of the envelope space, thereby generating a hexahedral envelope space with the determined length, width and height parameters.
[0103] Therefore, the embodiment of the present application generates an envelope coordinate system based on the connection direction, so that the generation of the envelope space has a clear direction reference, and determines the boundary of the envelope space according to the maximum size data of the fastener, thereby accurately generating an envelope space that can completely cover the fastener.
[0104] Figure 9 The process of the finite element automatic generation method in one embodiment of the present application is shown Figure 5 ,like Figure 9 As shown, the above S5 may include the following steps:
[0105] Step S51 , obtaining the three-dimensional coordinates of each entity node in the envelope space, and determining the three-dimensional distribution center point corresponding to all entity nodes according to the three-dimensional coordinates, so as to use the three-dimensional distribution center point as the main node of the rigid unit.
[0106] Specifically, the envelope space defines the connection area between the connected component and the fastener. Therefore, obtaining the 3D coordinates of each solid node within the envelope space provides the basis for subsequently determining the primary nodes of the rigid elements and accurately simulating the mechanical properties of the connection. More specifically, solid nodes are the basic elements that constitute the connected component in the finite element model and can be captured using the finite element mesh of the connected component.
[0107] It should be noted that the embodiment of the present application uses the three-dimensional distribution center points corresponding to all physical nodes as the main nodes of the rigid unit in the absence of special requirements. This is not used to limit the present application. In actual application scenarios, the method for determining the main node can also be set according to specific working conditions.
[0108] In step S53 , all entity nodes are used as a plurality of slave nodes of the rigid unit, and the plurality of slave nodes are respectively bound to the master node to generate a rigid unit according to the binding results.
[0109] Specifically, Figure 10 The rbe2 rigid element corresponding to the screw is shown, as Figure 10 As shown, screw G1 penetrates the first connected member A1 and the second connected member A2. More specifically, in HyperMesh software, the Tcl language command "createmark nodes 1 "by block" can be called to obtain all node IDs within the envelope space, and the command "*rigidlinkinodecalandcreate" can be called to reference the above node IDs to generate the RBE2 rigid element.
[0110] The embodiment of the present application divides the entity nodes of the connected parts by the envelope space. These entity nodes have rigid motion constraints with the fasteners. This constraint relationship simulates the mechanical behavior of the fasteners and the connected parts at the connection part in actual engineering. That is, when these nodes of the connected parts are subjected to external forces, they will maintain a relatively rigid motion state with the fasteners and will not cause non-rigid displacements such as relative sliding or separation. Then, according to the distribution of these entity nodes in the envelope space, the master nodes and slave nodes of the rigid unit are determined, and each slave node is connected to the master node to form a connection constraint, thereby automatically generating Figure 10 The rbe2 rigid element is shown.
[0111] Therefore, the embodiment of the present application determines the master node and slave node of the rigid unit according to the distribution of these physical nodes in the envelope space, and automatically generates the rigid unit corresponding to the fastener based on the master node and slave node, which greatly improves the generation efficiency of the rigid unit.
[0112] In addition, it should be noted that the embodiment of the present application is capable of generating rigid units of fasteners in batches for the finite element modeling process of the entire vehicle body. Specifically, in the HyperMesh software, the command *createmarkpanel solids is called in the Tcl language to select the geometric entity solid of the fastener, thereby obtaining the fastener index id, and correspondingly generating the fastener index list G = [G1, G2, G3, G4, G5, ... Gi]. In the process of automatically generating rigid units in batches, the fastener index list G is traversed and looped to repeat the above steps S1 to S5 for each fastener, thereby realizing the automated creation of connection parts for a large amount of geometric connection data, significantly shortening the modeling time and improving work efficiency.
[0113] Accordingly, please refer to Figure 11 The embodiment of the present application provides a finite element automatic generation device for a vehicle body connection part, wherein the connection part adopts an FDS or SPR connection method and is connected to the vehicle body by fasteners. The device includes
[0114] a direction determination module 100 for traversing each envelope surface of each fastener in the vehicle body, identifying a target end surface in the envelope surface during the traversal process, and determining a connection direction of the fastener based on the target end surface;
[0115] An envelope generation module 200 is configured to obtain outer contour parameters of the fastener and generate an envelope space of the fastener according to the connection direction and the outer contour parameters;
[0116] The rigid unit generation module 300 is used to determine the connected part corresponding to the fastener, and automatically generate the rigid unit corresponding to the fastener based on each entity node of the connected part in the envelope space, so as to perform finite element modeling of the FDS or SPR connection of the vehicle body through the rigid unit.
[0117] The automatic finite element generation method provided in this embodiment automatically traverses the envelope surface of the fastener to determine the connection direction and ensure the accurate generation of the envelope space. It then automatically generates rigid elements based on the physical nodes of the connected parts within the envelope space. This avoids the tedious operation of simulation engineers manually completing FDS or SPR connections one by one, significantly shortens the time for batch processing FDS or SPR connections in vehicle body finite element modeling, reduces manpower investment, and greatly improves simulation work efficiency.
[0118] In some embodiments of the present application, the direction determination module 100 includes:
[0119] a traversal unit 110, configured to traverse each of the envelope surfaces based on an index corresponding to each of the envelope surfaces, and obtain a first geometric area of each of the envelope surfaces based on a geometric feature of the fastener during the traversal process;
[0120] The identification unit 120 is configured to identify a target end face in the envelope surface according to the first geometric area.
[0121] In some embodiments of the present application, the identification unit 120 further includes:
[0122] The matching subunit 121 is configured to determine a reference area, match the first geometric area with the reference area, and determine the target end face in the envelope surface according to the matching result.
[0123] The process of determining the reference area includes: determining a second geometric area of a designated end face of the fastener according to standard geometric parameters of the fastener, and using the second geometric area as the reference area.
[0124] In some embodiments of the present application, the direction determination module 100 further includes:
[0125] The edge acquisition unit 130 is used to acquire the peripheral edge line of the target end surface and extract any arc line in the peripheral edge line;
[0126] The normal vector generating unit 140 is used to determine the center point corresponding to the arc line and generate a normal vector corresponding to the target end face at the position of the center point, so as to determine the connection direction of the fastener according to the normal vector.
[0127] In some embodiments of the present application, the envelope generation module 200 further includes:
[0128] An outer contour determining unit 210 is configured to determine maximum dimension data of the fastener based on standard geometric parameters of the fastener, and determine outer contour parameters based on the maximum dimension data; wherein the outer contour parameters are greater than or equal to the maximum dimension data;
[0129] The envelope generating unit 220 is configured to generate an envelope coordinate system according to the connection direction, and generate the envelope space in the envelope coordinate system according to the outer contour parameters.
[0130] In some embodiments of the present application, the rigid unit generation module 300 further includes:
[0131] a master node determination unit 310 configured to obtain the three-dimensional coordinates of each of the physical nodes in the envelope space, and determine the three-dimensional distribution center point corresponding to all of the physical nodes according to the three-dimensional coordinates, so as to use the three-dimensional distribution center point as the master node of the rigid unit;
[0132] The binding unit 320 is configured to use all the physical nodes as a plurality of slave nodes of the rigid unit, and to bind the plurality of slave nodes to the master node respectively, so as to generate the rigid unit according to the binding results.
[0133] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.
[0134] The finite element automatic generation device in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.
[0135] Therefore, the finite element automatic generation device proposed in the embodiment of the present application ensures the generation of accurate envelope space by automatically traversing the envelope surface to determine the connection direction, automatically generating the envelope space, and automatically generating rigid units based on the nodes of the connected parts, and automatically generates rigid units based on the physical nodes of the connected parts in the envelope space, avoiding the tedious operation of simulation engineers manually completing FDS or SPR connections one by one, greatly shortening the time for batch processing of FDS or SPR connections in vehicle body finite element modeling, reducing manpower input, and greatly improving simulation work efficiency.
[0136] See also Figure 12 , Figure 12 This is a schematic diagram of the structure of a computer device provided in an embodiment of the present application. Figure 12 As shown, the computer device includes: one or more processors 10, memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components utilize different buses to communicate with each other and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in the memory or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Equally, multiple computer devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 12 A processor 10 is taken as an example.
[0137] The processor 10 may be a central processing unit, a network processor, or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic, or any combination thereof.
[0138] The memory 20 stores instructions that can be executed by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.
[0139] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.
[0140] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid-state drive; the memory 20 may also include a combination of the above types of memory.
[0141] The computer device further includes a communication interface 30 for the computer device to communicate with other devices or a communication network.
[0142] The embodiments of the present application also provide a computer-readable storage medium. The above-mentioned method according to the embodiment of the present application can be implemented in hardware, firmware, or implemented as a computer code that can be recorded in a storage medium, or implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state drive, etc.; further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that a computer, a processor, a microprocessor controller or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor or hardware, the method shown in the above embodiment is implemented.
[0143] An embodiment of the present application provides a computer program product, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform a method according to any embodiment of the present application.
[0144] Although the embodiments of the present application have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations shall fall within the scope defined by the appended claims.
[0145] The devices, modules, or units described in the above embodiments may be implemented by computer chips or entities, or by products having certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.
[0146] For the convenience of description, the above devices are described as being divided into various units according to their functions. Of course, when implementing this application, the functions of each unit can be implemented in the same or multiple software and / or hardware.
[0147] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, devices (systems), or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0148] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.
[0149] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.
[0150] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.
[0151] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.
[0152] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiments are generally similar to the method embodiments, so the description is relatively simple. For relevant parts, refer to the description of the method embodiments.
[0153] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.
[0154] Although the embodiments of the present application have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations shall fall within the scope defined by the appended claims.
Claims
1. A method for automatically generating finite elements of vehicle body connection parts, characterized in that: The connection portion adopts an FDS or SPR connection method and is connected to the vehicle body via fasteners. The method includes: Traversing each envelope surface of each fastener in the vehicle body to identify a target end surface in the envelope surface during the traversal process, and determining a connection direction of the fastener according to the target end surface; Acquiring outer contour parameters of the fastener, and generating an envelope space of the fastener according to the connection direction and the outer contour parameters; A connected part corresponding to the fastener is determined, and a rigid unit corresponding to the fastener is automatically generated according to each entity node of the connected part in the envelope space, so as to perform finite element modeling of the FDS or SPR connection of the vehicle body through the rigid unit.
2. The method according to claim 1, characterized in that The traversing of each envelope surface of each fastener in the vehicle body to identify a target end surface in the envelope surface during the traversal process includes: Traversing each of the envelope surfaces based on an index corresponding to each of the envelope surfaces, and obtaining a first geometric area of each of the envelope surfaces based on a geometric feature of the fastener during the traversal process; A target end surface in the envelope surface is identified based on the first geometric area.
3. The method according to claim 2, characterized in that The step of identifying a target end face in the envelope surface according to the first geometric area includes: A reference area is determined, the first geometric area is matched with the reference area, and the target end face is determined in the envelope surface according to the matching result.
4. The method according to claim 3, characterized in that The process of determining the reference area includes: A second geometric area of a designated end face of the fastener is determined according to standard geometric parameters of the fastener, and the second geometric area is used as the reference area.
5. The method according to claim 1, wherein Determining the connection direction of the fastener according to the target end face includes: Obtaining the outer edge line of the target end face, and extracting any arc line in the outer edge line; A center point corresponding to the arc line is determined, and a normal vector corresponding to the target end face is generated at the position of the center point, so as to determine the connection direction of the fastener according to the normal vector.
6. The method according to claim 1, characterized in that The obtaining of the outer contour parameters of the fastener and generating the envelope space of the fastener according to the connection direction and the outer contour parameters includes: Determining maximum dimension data of the fastener according to standard geometric parameters of the fastener, and determining the outer contour parameters according to the maximum dimension data; wherein the outer contour parameters are greater than or equal to the maximum dimension data; An envelope coordinate system is generated according to the connection direction, and the envelope space is generated in the envelope coordinate system according to the outer contour parameters.
7. The method according to claim 1, characterized in that The automatically generating a rigid unit corresponding to the fastener according to each entity node of the connected component in the envelope space includes: Obtaining the three-dimensional coordinates of each of the physical nodes in the envelope space, and determining the three-dimensional distribution center point corresponding to all the physical nodes according to the three-dimensional coordinates, so as to use the three-dimensional distribution center point as the main node of the rigid unit; All the entity nodes are used as a plurality of slave nodes of the rigid unit, and a plurality of the slave nodes are respectively bound to the master node, so as to generate the rigid unit according to the binding results.
8. The method according to claim 1, characterized in that Each of the envelope surfaces of the fastener is determined by: obtaining geometric characteristics of the fastener; The envelope surfaces of the fasteners are determined according to geometric features of the fasteners.
9. A finite element automatic generation device for vehicle body connection parts, characterized in that: The connection part adopts the FDS or SPR connection method and is connected to the vehicle body through fasteners. The device includes: a direction determination module, configured to traverse each envelope surface of each fastener in the vehicle body, identify a target end surface in the envelope surface during the traversal process, and determine a connection direction of the fastener based on the target end surface; an envelope generating module, configured to obtain outer contour parameters of the fastener and generate an envelope space of the fastener according to the connection direction and the outer contour parameters; A rigid unit generation module is used to determine the connected part corresponding to the fastener, and automatically generate a rigid unit corresponding to the fastener based on each entity node of the connected part in the envelope space, so as to perform finite element modeling of the FDS or SPR connection of the vehicle body through the rigid unit.
10. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the finite element automatic generation method for the vehicle body connection part according to any one of claims 1 to 8 by executing the computer instructions.