Equivalent finite element modeling method and device for connecting bolt, electronic equipment and medium

Abstract

The invention relates to an equivalent finite element modeling method and device for a connecting bolt, electronic equipment and a medium. Comprising the following steps: acquiring a geometric model of a current bolt and geometric models of a plurality of connected structures corresponding to the current bolt, and determining a connection type between the connected structures; the geometric model of the current bolt is equivalent to a one-dimensional beam unit meeting the preset target diameter condition based on the connection types of the multiple connected structures; and establishing an annular area around the bolt hole of the geometric model of each connected structure, and connecting all nodes of the annular area with nodes of the one-dimensional beam unit penetrating through the annular area to generate an equivalent finite element model of the connecting bolts. Therefore, the problems that in the prior art, bolt connection finite element modeling is complex, the calculation efficiency is low, the model scale is large, and misconvergence is prone to occurring are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical engineering and finite element analysis, and particularly relates to an equivalent finite element modeling method and device for connecting bolts, an electronic device and a medium. BACKGROUND

[0002] With the increasing demand for lightweight and high-performance structures in industries such as automobiles and aerospace, the design and optimization of plate and shell structures and complex connection systems become particularly important. Finite element modeling technology plays a key role in these fields, helping engineers predict structural performance in the early stages of product development, optimize design parameters, and improve product quality, reduce costs, and shorten development cycles. In finite element modeling, bolt connection is a very common connection method in mechanical structures, and the accuracy of its modeling has a significant impact on the simulation results of the entire structure.

[0003] In related technologies, the finite element modeling method for bolt connection usually involves establishing the bolt and nut as a hexahedral solid element, establishing the contact pair between the bolt and the connected parts, and setting the contact relationship and friction coefficient. However, this method has obvious limitations when dealing with large-scale complex structures, such as automobile chassis frame assemblies, including complex finite element modeling process, low computational efficiency, large model size, and easy divergence, which need to be solved. SUMMARY

[0004] The present application provides an equivalent finite element modeling method and device for connecting bolts, an electronic device and a medium to solve the problems of complex finite element modeling for bolt connection, low computational efficiency, large model size and easy divergence in the prior art, so that the modeling and calculation of bolt connection can be efficiently and quickly completed in large-scale complex structure finite element analysis, significantly improving the efficiency of engineering design and analysis.

[0005] To achieve the above-mentioned purpose, the first aspect of the present application provides an equivalent finite element modeling method for connecting bolts, comprising the following steps: Obtain the geometric model of the current bolt and the geometric model of a plurality of connected structures corresponding to the current bolt, and determine the connection type between the connected structures; Based on the connection type between a plurality of connected structures, the geometric model of the current bolt is equivalent to a one-dimensional beam element that satisfies a preset target diameter condition, wherein the diameter of the beam element section located between adjacent connected structures is set to a first preset diameter length, and the diameter of the beam element section located inside the connected structure is set to a second preset diameter length, and the first preset diameter length is greater than the second preset diameter length; An annular region is established around the bolt hole of the geometric model of each connected structure, and all nodes of the annular region are connected with the nodes of the one-dimensional beam element passing through the annular region, to generate an equivalent finite element model of the connecting bolt.

[0006] According to one embodiment of the present application, the annular region established around the bolt hole of the geometric model of each connected structure comprises: determining whether there are plate shell members and / or solid members in the plurality of connected structures; in the case that the plate shell members exist in the plurality of connected structures, performing a middle surface abstraction operation on the plate shell members to generate intermediate curved surfaces, and performing a geometric expansion operation on the bolt connection regions of the intermediate curved surfaces to generate first node coupling regions; and / or, in the case that the solid members exist in the plurality of connected structures, performing a geometric expansion operation on the bolt connection regions of the solid members to generate second node coupling regions, wherein the first node coupling regions and the second node coupling regions constitute the annular region.

[0007] According to one embodiment of the present application, the connection type between the plurality of connected structures is plate shell-plate shell connection, and the equivalent processing of the geometric model of the current bolt into a one-dimensional beam element satisfying a preset target diameter condition based on the connection type between the plurality of connected structures comprises: a first one-dimensional beam element passing through all plate shell members is established, and the diameter of the first one-dimensional beam element is set as the first preset diameter length.

[0008] According to one embodiment of the present application, the connection type between the plurality of connected structures is plate shell-solid connection, and the equivalent processing of the geometric model of the current bolt into a one-dimensional beam element satisfying a preset target diameter condition based on the connection type between the plurality of connected structures comprises: a second one-dimensional beam element passing through the plate shell member and extending into the interior of the solid member is established; the diameter of a first beam element section located between the plate shell member and the solid member and a second beam element section located in the interior of the plate shell member is set as the first preset diameter length, and the diameter of a third beam element section located in the interior of the solid member is set as the second preset diameter length.

[0009] According to one embodiment of the present application, the connection type between the plurality of connected structures is solid-solid connection, and the equivalent processing of the geometric model of the current bolt into a one-dimensional beam element satisfying a preset target diameter condition based on the connection type between the plurality of connected structures comprises: establishing a third one-dimensional beam element which passes through the first solid member and the second solid member in sequence and extends to the inside of the second solid member; setting the diameter of a fourth beam element section between the first solid member and the second solid member as the first preset diameter length, and setting the diameter of a fifth beam element section inside the first solid member and the diameter of a sixth beam element section inside the second solid member as the second preset diameter length.

[0010] According to an embodiment of the present application, the connection type between the plurality of connected structures is solid-solid connection and there is an internal thread in the solid member, and the equivalent processing of the geometric model of the current bolt into a one-dimensional beam element which satisfies the preset target diameter condition based on the connection type between the plurality of connected structures comprises: establishing a fourth one-dimensional beam element which passes through the plate-shell member and extends to the inside of the solid member with the internal thread; setting the diameter of a seventh beam element section between the plate-shell member and the solid member with the internal thread and the diameter of an eighth beam element section inside the plate-shell member as the first preset diameter length, and setting the diameter of a ninth beam element section inside the solid member with the internal thread as the second preset diameter length.

[0011] According to the equivalent finite element modeling method of a connecting bolt proposed in the embodiments of the present application, the geometric model of a current bolt and the geometric models of a plurality of connected structures corresponding to the current bolt are obtained, and the connection type between the connected structures is determined; the geometric model of the current bolt is equivalent to a one-dimensional beam element which satisfies a preset target diameter condition based on the connection type between the plurality of connected structures, wherein the diameter of a beam element section between adjacent connected structures is set as a first preset diameter length, and the diameter of a beam element section inside a connected structure is set as a second preset diameter length; a ring-shaped area is established around the bolt hole of the geometric model of each connected structure, and all nodes of the ring-shaped area are connected to the nodes of the one-dimensional beam element passing through the ring-shaped area, to generate an equivalent finite element model of the connecting bolt. Thus, the problems of complex finite element modeling of bolt connection, low calculation efficiency, large model size and easy non-convergence in the prior art are solved, so that the modeling and calculation of bolt connection can be efficiently and quickly completed in the finite element analysis of large-scale complex structures, and the efficiency of engineering design and analysis is significantly improved.

[0012] To achieve the above object, a second aspect embodiment of the present application provides an equivalent finite element modeling device of a connecting bolt, comprising: The first processing module is configured to acquire a geometric model of a current bolt and geometric models of a plurality of connected structures corresponding to the current bolt, and determine a connection type between the connected structures; The second processing module is configured to, based on the connection type between the plurality of connected structures, equivalently process the geometric model of the current bolt into a one-dimensional beam element satisfying a preset target diameter condition, wherein a diameter of a beam element section located between adjacent connected structures is set as a first preset diameter length, and a diameter of a beam element section located inside the connected structure is set as a second preset diameter length, the first preset diameter length being greater than the second preset diameter length. The generating module is configured to establish an annular area around a bolt hole of each geometric model of the connected structures, and connect all nodes of the annular area with nodes of the one-dimensional beam element passing through the annular area, to generate an equivalent finite element model of a connecting bolt.

[0013] According to an embodiment of the present application, the generating module is specifically configured to: determine whether there are plate shell members and / or solid members in the plurality of connected structures; in a case where the plate shell members exist in the plurality of connected structures, perform a middle surface abstraction operation on the plate shell members to generate an intermediate curved surface, and perform a geometric expansion operation on a bolt connection area of the intermediate curved surface to generate a first node coupling area; and / or, in a case where the solid members exist in the plurality of connected structures, perform a geometric expansion operation on a bolt connection area of the solid members to generate a second node coupling area, wherein the first node coupling area and the second node coupling area constitute the annular area.

[0014] According to an embodiment of the present application, the connection type between the plurality of connected structures is plate shell-plate shell connection, and the second processing module is specifically configured to: establish a first one-dimensional beam element penetrating all plate shell members, and set a diameter of the first one-dimensional beam element as the first preset diameter length.

[0015] According to an embodiment of the present application, the connection type between the plurality of connected structures is plate shell-solid connection, and the second processing module is specifically configured to: establish a second one-dimensional beam element penetrating the plate shell member and extending into the solid member; set a diameter of a first beam element section located between the plate shell member and the solid member and a diameter of a second beam element section located inside the plate shell member as the first preset diameter length, and set a diameter of a third beam element section located inside the solid member as the second preset diameter length.

[0016] According to one embodiment of the present application, the connection type between the plurality of connected structures is a solid-solid connection, and the second processing module is specifically configured to: establish a third one-dimensional beam element that sequentially passes through the first solid member and the second solid member and extends to the inside of the second solid member; set the diameter of a fourth beam element section located between the first solid member and the second solid member to the first preset diameter length, and set the diameters of a fifth beam element section located inside the first solid member and a sixth beam element section located inside the second solid member to the second preset diameter length.

[0017] According to one embodiment of the present application, the connection type between the plurality of connected structures is a solid-solid connection and there is an internal thread in the solid member, and the second processing module is specifically configured to: establish a fourth one-dimensional beam element that passes through the plate shell member and extends to the inside of the solid member with the internal thread; set the diameters of a seventh beam element section located between the plate shell member and the solid member with the internal thread and an eighth beam element section located inside the plate shell member to the first preset diameter length, and set the diameter of a ninth beam element section located inside the solid member with the internal thread to the second preset diameter length.

[0018] According to the equivalent finite element modeling device for a connecting bolt provided by the embodiment of the present application, the geometric model of the current bolt and the geometric models of a plurality of connected structures corresponding to the current bolt are obtained, and the connection type between the connected structures is determined. Based on the connection type between the plurality of connected structures, the geometric model of the current bolt is equivalent to a one-dimensional beam element that meets a preset target diameter condition, wherein the diameter of a beam element section located between adjacent connected structures is set to a first preset diameter length, and the diameter of a beam element section located inside a connected structure is set to a second preset diameter length. An annular area is established around the bolt hole of each connected structure, and all nodes of the annular area are connected to the nodes of the one-dimensional beam element passing through the annular area to generate an equivalent finite element model of the connecting bolt. Thus, the problems of complex finite element modeling, low calculation efficiency, large model size, and easy non-convergence of the prior art are solved, so that the modeling and calculation of bolt connection can be efficiently and quickly completed in large-scale complex structure finite element analysis, and the efficiency of engineering design and analysis is significantly improved.

[0019] To achieve the above object, the third aspect of the present application provides an electronic device, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the equivalent finite element modeling method of the connecting bolt as described in the above embodiments.

[0020] To achieve the above object, the fourth aspect of the present application provides a computer readable storage medium, which stores a computer program executable by a processor to implement the equivalent finite element modeling method of the connecting bolt as described in the above embodiments.

[0021] The additional aspects and advantages of the present application will be partially given in the following description, partially become obvious from the following description, or be known by the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0022] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, taken in conjunction with the accompanying drawings, in which: Figure 1 A flow chart of the equivalent finite element modeling method of the connecting bolt according to an embodiment of the present application; Figure 2 A flow chart of another equivalent finite element modeling method of the connecting bolt according to an embodiment of the present application; Figure 3 A schematic diagram of the relationship between the outer diameter of the processed gasket and the screw rod diameter according to an embodiment of the present application; Figure 4 A schematic diagram of the bolt connecting 3-layer plate shell structure according to an embodiment of the present application; Figure 5 A schematic diagram of the equivalent simplified modeling of the bolt connecting (shell-shell) according to an embodiment of the present application; Figure 6 A schematic diagram of the bolt connecting plate shell-solid structure according to an embodiment of the present application; Figure 7 A schematic diagram of the equivalent simplified modeling of the bolt connecting (shell-solid) according to an embodiment of the present application; Figure 8 A schematic diagram of the bolt connecting solid-solid structure according to an embodiment of the present application; Figure 9 A schematic diagram of the equivalent simplified modeling of the bolt connecting (solid-solid) according to an embodiment of the present application; Figure 10 A schematic diagram of the bolt connecting plate shell-solid (with internal thread in the solid) structure according to an embodiment of the present application; Figure 11Equivalent simplified modeling schematic diagram of bolt connection (shell-solid, and internal thread in the solid) according to an embodiment of the present application; Figure 12 Block schematic diagram of equivalent finite element modeling device of connecting bolt according to an embodiment of the present application; Figure 13 Structure schematic diagram of electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] The embodiments of the present application are described in detail below with reference to the accompanying drawings. The embodiments shown in the drawings are examples for explaining the present application and should not be construed as limiting the present application.

[0024] The equivalent finite element modeling method, device, electronic device and medium of connecting bolt according to the embodiments of the present application are described below with reference to the accompanying drawings.

[0025] Figure 1 Flow chart of the equivalent finite element modeling method of connecting bolt according to an embodiment of the present application.

[0026] Before introducing the equivalent finite element modeling method of connecting bolt according to the embodiments of the present application, the related technical background is briefly introduced.

[0027] When finite element modeling simulation is performed, modeling and calculation of bolts and pre-tightening force are relatively common. The common method is to establish hexahedral solid elements for the bolts and nuts, to establish contact pairs for the bolts, nuts and connected parts, to set contact relationship and friction coefficient, and to apply pre-tightening force. This modeling method is most consistent with the actual situation and can calculate information such as pressure distribution in the contact area and stress of the bolt. However, the disadvantages of this method are complex modeling, long cycle, large model size, long calculation cycle, and often non-convergence. For relatively simple and small-scale structures, this modeling method is feasible, but for large chassis frame assembly structures with a large number of bolts, if contact relationship is established between each bolt and the frame, the model size is large, the calculation time is too long, and convergence is difficult.

[0028] Therefore, the current modeling and simulation methods for connecting bolts in large-scale computational models (such as chassis frame assembly structures with unit scale reaching millions) have the following problems: (1) If solid units are used to build real bolts, the scale of the frame assembly structure simulation model will increase further, and the computational efficiency will be extremely low; (2) After building a real bolt structure, it is necessary to establish the contact relationship between the bolts and nuts and the connected structure. Assuming that a frame assembly has 100 bolts, then at least 200 contact surfaces and 200 pairs of contact relationships need to be established, which leads to low modeling efficiency and the computational model is not easy to converge.

[0029] Based on the aforementioned problems, this application proposes an equivalent finite element modeling method for connecting bolts. This method obtains the geometric models of the current bolt and its corresponding multiple connected structures, determining the connection type between the connected structures. Based on the connection type, the current bolt geometric model is equivalent to a one-dimensional beam element satisfying a preset target diameter condition. The diameter of the beam element segment between adjacent connected structures is set as a first preset diameter length, and the diameter of the beam element segment within the connected structure is set as a second preset diameter length. An annular region is constructed around the bolt hole of each connected structure geometric model, and all nodes in the annular region are connected to the one-dimensional beam element nodes passing through this region, generating an equivalent finite element model of the connecting bolt. Therefore, without increasing the scale of the simulation calculation model or establishing contact relationships, the engineering simulation accuracy of the vehicle frame assembly structure can be met. This solves the problems of complex finite element modeling of bolt connections, low computational efficiency, large model size, and tendency to non-converge in existing technologies. It enables efficient and rapid modeling and calculation of bolt connections in the finite element analysis of large-scale complex structures, significantly improving the efficiency of engineering design and analysis.

[0030] The equivalent finite element modeling method for connecting bolts proposed in the embodiments of this application will be described in detail below.

[0031] For example, such as Figure 1 As shown, the equivalent finite element modeling method for this connecting bolt includes the following steps: In step S101, the geometric model of the current bolt and the geometric models of multiple connected structures corresponding to the current bolt are obtained, and the connection type between the connected structures is determined.

[0032] Specifically, a three-dimensional geometric model of the current bolt and geometric models of a plurality of connected structures connected to the current bolt are imported by using a finite element software (such as Hypermesh, a finite element model pre-processing tool), wherein the three-dimensional geometric model of the current bolt includes a shank and a head of the bolt, and the connected structures can be a plate shell structure (such as a thin plate of an automobile chassis), a solid structure (such as a bracket or a beam), or a combination of the two. By analyzing the geometric characteristics and connection modes of the connected structures, the connection type between them can be determined, including, for example, plate shell-plate shell connection, i.e., both connected structures are plate shell members; plate shell-solid connection, i.e., one connected structure is a plate shell member and the other is a solid member; solid-solid connection, i.e., both connected structures are solid members; and plate shell-solid (with internal threads) connection, i.e., one connected structure is a plate shell member and the other is a solid member, and the solid member has internal threads.

[0033] Further, after determining the connection type, the plate shell structure and the solid structure are meshed to generate a discretized model that can be used for finite element analysis. For the plate shell member, mapping mesh or swept mesh technology can be used to divide the mesh using quadrilateral elements. Compared with triangular elements, quadrilateral elements have fewer degrees of freedom at the same mesh density, thereby reducing the amount of calculation. For the solid member, automatic subdivision can be performed using second-order tetrahedral elements. Second-order tetrahedral elements are a kind of three-dimensional elements, which are usually used to simulate complex-shaped solid structures. For complex geometric shapes, second-order tetrahedral elements can automatically adapt without the need for manual adjustment of the mesh.

[0034] In step S102, based on the connection type between the plurality of connected structures, the geometric model of the current bolt is equivalently processed into a one-dimensional beam element that satisfies a preset target diameter condition, wherein the diameter of a beam element section located between adjacent connected structures is set to a first preset diameter length, and the diameter of a beam element section located inside a connected structure is set to a second preset diameter length, the first preset diameter length being greater than the second preset diameter length.

[0035] The first preset diameter length and the second preset diameter length can be pre-set by researchers in the field, obtained through a finite number of experiments, or obtained through a finite number of computer simulations, and are not limited in particular.

[0036] Specifically, after obtaining the connection type between the plurality of connected structures of the current bolt, the equivalent processing mode of the geometric model of the current bolt under different connection types can be determined according to the connection type between the connected structures (i.e., shell-shell connection, shell-solid connection, solid-solid connection, shell-solid (with internal threads) connection), that is, the geometric model of the current bolt is equivalent to a one-dimensional beam element (i.e., Beam element, usually 6-DOF Timoshenko beam). The beam element is a simplified model used to simulate the mechanical behavior of the bolt, especially its stiffness and flexibility. Among them, the diameter of the beam element section located between adjacent connected structures is set to a first preset diameter length, which is usually large, used to simulate the stiffness of the bolt connection area; the diameter of the beam element section located inside the connected structure is set to a second preset diameter length, which is usually small, used to simulate the flexibility of the bolt inside the connected structure.

[0037] For example, assuming the nominal diameter of the bolt is D, the first preset diameter length can be 2.5D, and the second preset diameter length can be D.

[0038] By equivalent the geometric model of the current bolt to a one-dimensional beam element and setting different beam element diameters according to the connection type, the modeling process can be significantly simplified, the calculation efficiency can be improved, and the accuracy and reliability of the model can be ensured.

[0039] For ease of understanding, how to equivalent the geometric model of the current bolt to a one-dimensional beam element that meets the preset target diameter condition based on the connection type between the plurality of connected structures will be described in detail below.

[0040] Optionally, in some embodiments, the connection type between the plurality of connected structures is shell-shell connection, and equivalent processing the geometric model of the current bolt to a one-dimensional beam element that meets the preset target diameter condition based on the connection type between the plurality of connected structures includes: establishing a first one-dimensional beam element that penetrates all shell members, and setting the diameter of the first one-dimensional beam element to a first preset diameter length.

[0041] Specifically, in the case where the connection type between the plurality of connected structures is shell-shell connection (i.e., all connected structures are thin-walled shells (such as body sheet metal, shell element region of frame longitudinal beam / beam), no solid, bolt axis perpendicular to each shell midplane, forming a multi-layer shell-shell composite connection), the entire bolt (i.e., the geometric model of the current bolt) can be equivalent to a beam (i.e., the first one-dimensional beam element) with a diameter of a first preset diameter length (2.5D) and at least three sections, penetrating all shell midplanes along the bolt axis direction, starting at the outermost shell on the bolt head side, and ending at the outermost shell on the nut side.

[0042] Thus, the entity bolt, washer and contact pair no longer appear in the model, only a beam with a diameter of 2.5 D (2.5 times the nominal diameter) is used, the number of units is reduced from hundreds to single digits, the error of the rigid body and the classical entity bolt model is less than 5% (satisfying the engineering precision), and the calculation convergence is greatly improved.

[0043] Alternatively, in other embodiments, the connection type between the plurality of connected structures is a shell-solid connection, and based on the connection type between the plurality of connected structures, the geometric model of the current bolt is equivalently processed into a one-dimensional beam element that satisfies a preset target diameter condition, including: establishing a second one-dimensional beam element that penetrates the shell member and extends into the interior of the solid member; setting the diameter of the first beam element section located between the shell member and the solid member and the second beam element section located in the interior of the shell member to a first preset diameter length, and setting the diameter of the third beam element section located in the interior of the solid member to a second preset diameter length.

[0044] Specifically, in the case where the connection type between the plurality of connected structures is a shell-solid connection (i.e., one side is a thin-walled shell (such as a vehicle body sheet metal), the other side is a three-dimensional solid (such as a bracket, a subframe boss), the bolt penetrates from the shell side and is screwed into the solid threaded hole, and usually there is no nut (or blind hole)), the entire bolt (i.e., the geometric model of the current bolt) can be equivalently processed into a one-dimensional beam element (i.e., a second one-dimensional beam element) that penetrates the shell member and extends into the interior of the solid member. The beam element starts from the surface of the shell member, penetrates the shell member, enters the interior of the solid member, and ends at the effective length of the bolt, with at least three sections throughout to ensure bending flexibility. For the design of the diameter of the second one-dimensional beam element, the embodiments of the present application set the diameter of the beam element section (i.e., the first beam element section) located between the shell member and the solid member to a first preset diameter length (2.5 D), simulate the high stiffness of the bolt connection area, set the diameter of the beam element section (i.e., the second beam element section) located in the interior of the shell member to the first preset diameter length (2.5 D) as well, ensure the connection stiffness in the interior of the shell member, and prevent local stress concentration, and set the diameter of the beam element section (i.e., the third beam element section) located in the interior of the solid member to a second preset diameter length (D), simulate the actual flexibility of the bolt in the interior of the solid member.

[0045] Thus, for the case where the connection type is a shell-solid connection, the bolt is made into a beam with "thick ends and thin middle", i.e., the shell area and the shell-solid interface are captured with 2.5 D to simulate the washer effect, and the embedded section in the solid is restored to D to restore the flexibility of the screw rod, so that the model can be greatly simplified while ensuring precision.

[0046] Optionally, in other embodiments, the connection type between the plurality of connected structures is a solid-solid connection, and based on the connection type between the plurality of connected structures, the geometric model of the current bolt is equivalently processed as a one-dimensional beam element that meets the preset target diameter condition, including: establishing a third one-dimensional beam element that sequentially passes through the first solid member and the second solid member and extends into the interior of the second solid member; setting the diameter of a fourth beam element section located between the first solid member and the second solid member to a first preset diameter length, and setting the diameters of a fifth beam element section located in the interior of the first solid member and a sixth beam element section located in the interior of the second solid member to a second preset diameter length.

[0047] Specifically, in the case where the connection type between the plurality of connected structures is a solid-solid connection (for example, two solid supports or beams in an automobile chassis, a bolt passing through the two solid members to connect them together), the entire bolt (i.e., the geometric model of the current bolt) can be equivalently processed as a beam element (i.e., a third one-dimensional beam element) that sequentially passes through the first solid member and the second solid member and extends into the interior of the second solid member. The third one-dimensional beam element starts from the surface of the first solid member, passes through the contact surface of the two solid members, and ends at the effective length of the bolt in the interior of the second solid member, with at least three sections throughout to ensure bending flexibility. For the design of the diameter of the third one-dimensional beam element, the diameter of the beam element section (i.e., the fourth beam element section) located between the first solid member and the second solid member is set to a first preset diameter length (2.5D) to simulate the high stiffness of the connection region, the diameter of the beam element section (i.e., the fifth beam element section) located in the interior of the first solid member is set to a second preset diameter length (D) to simulate the flexibility of the bolt in the solid member, and the diameter of the beam element section (i.e., the sixth beam element section) located in the interior of the second solid member is also set to the second preset diameter length (D) to simulate the flexibility of the bolt in the solid member.

[0048] Thus, for the case where the connection type is a solid-solid connection, the bolt is equivalently processed as a one-dimensional beam element that sequentially passes through the two solid members and extends into the interior, wherein the section diameter between the two solid members is set to 2.5D, and the section diameter in the interior of each solid member is set to 1.0D, and the connection stiffness and calculation accuracy are ensured through segmentation and node coupling.

[0049] Optionally, in some other embodiments, the connection type between the plurality of connected structures is solid-solid connection and there is an internal thread in the solid member, based on the connection type between the plurality of connected structures, the geometric model of the current bolt is equivalent to a one-dimensional beam element satisfying a preset target diameter condition, including: establishing a fourth one-dimensional beam element penetrating through the panel shell member and extending to the inside of the solid member with the internal thread; setting the diameters of a seventh beam element section between the panel shell member and the solid member with the internal thread and an eighth beam element section inside the panel shell member to a first preset diameter length, and setting the diameter of a ninth beam element section inside the solid member with the internal thread to a second preset diameter length.

[0050] Specifically, in the case where the connection type between the plurality of connected structures is solid-solid connection and there is an internal thread in the solid member (one side is a thin-walled panel shell (such as a vehicle body sheet metal), the other side is a three-dimensional solid, and the thread is directly machined in the solid hole (without a nut, the bolt is screwed into a blind hole or a through hole)), the whole bolt (i.e. the geometric model of the current bolt) can be equivalent to a beam element (i.e. the fourth one-dimensional beam element) from the outside of the panel shell to the panel shell surface into the solid with the internal thread, to the bottom of the effective depth of the thread, at least three sections, to ensure bending flexibility. For the design of the diameter of the third one-dimensional beam element, the embodiments of the present application set the diameter of the beam element section (i.e. the seventh beam element section) between the panel shell member and the solid member with the internal thread to a first preset diameter length (2.5D), for simulating the high stiffness of the connection area, set the diameter of the beam element section (i.e. the eighth beam element section) inside the panel shell member to the first preset diameter length (2.5D) as well, to maintain the uniform diffusion of the panel shell surface load, and set the diameter of the beam element section (i.e. the ninth beam element section) inside the solid member with the internal thread to a second preset diameter length (D), to restore the real flexibility of the screw rod and avoid excessive stiffness.

[0051] Thus, for the case where the connection type is solid-solid connection and there is an internal thread in the solid member, the bolt is equivalent to a beam with "thick outside and thin inside", i.e. the panel shell area and the panel shell-solid interface are simulated with a 2.5D gasket effect, and the buried thread area is simulated with D to restore the flexibility of the screw rod.

[0052] In step S103, an annular area is established around the bolt hole of the geometric model of each connected structure, and all nodes of the annular area are connected with the nodes of the one-dimensional beam element penetrating through the annular area, to generate an equivalent finite element model of the connecting bolt.

[0053] It can be understood that in the finite element analysis, the modeling of the bolted structure needs to consider the contact relationship and load transmission between the bolt and the connected structure. In order to more accurately simulate these relationships, the bolt hole periphery of the geometric model of each connected structure can be geometrically processed, and two annular regions (i.e. Washer regions) are established around the bolt hole. In actual engineering, washers are usually used in bolt connection to uniformly distribute the load and prevent local stress concentration. By establishing an annular region around the bolt hole, the stiffness and load distribution of the bolted connection area can be more accurately simulated. Subsequently, the nodes of the annular region are connected with the nodes of the one-dimensional beam element, which can ensure that the load can be correctly transmitted.

[0054] Specifically, in the geometric model of each connected structure, the position of the bolt hole is found, and then two annular regions (Washer regions) are established around the bolt hole, that is, an inner circle washer region is set around the bolt hole, the inner circle diameter of which is the same as the diameter of the bolt hole, and the outer circle diameter is usually set to 1.5 times the diameter of the bolt shank. An outer circle washer region is further set outside the inner circle washer region, the inner circle diameter of which is the same as the outer circle diameter of the inner circle washer region, and the outer circle diameter is usually set to 2.5 times the diameter of the bolt shank. By setting two washer regions, the effect of the washer in actual connection can be more accurately simulated, local stress concentration can be reduced, and the accuracy of the model can be improved. Subsequently, all nodes of the annular region are connected with the nodes of the one-dimensional beam element passing through the annular region using a rigid body element (such as Rbe2), wherein all nodes of the annular region are slave points of the rigid body element, and the nodes of the one-dimensional beam element in the Washer plane are master points of the rigid body element. After connection, the connection relationship of all nodes and elements in the model is checked to ensure the integrity and accuracy of the model, so as to obtain the final equivalent finite element model of the connected bolt.

[0055] The following will explain in detail how to establish an annular region around the bolt hole of each connected structure.

[0056] As a possible implementation manner, in some embodiments, the establishment of the annular region around the bolt hole of each connected structure includes: judging whether there are plate shell members and / or solid members in the plurality of connected structures; in the case that there are plate shell members in the plurality of connected structures, performing a middle surface abstraction operation on the plate shell members to generate an intermediate curved surface, and performing a geometric expansion operation on the bolt connection region of the intermediate curved surface to generate a first node coupling region; and / or in the case that there are solid members in the plurality of connected structures, performing a geometric expansion operation on the bolt connection region of the solid members to generate a second node coupling region, wherein the first node coupling region and the second node coupling region constitute the annular region.

[0057] Specifically, first, it can be checked whether there are plate shell members and / or solid members in the connected structure, if there are plate shell members in the connected structure, the plate shell members can be subjected to a middle surface abstraction operation to generate an intermediate curved surface, wherein the middle surface abstraction refers to simplifying a three-dimensional thin plate structure into a two-dimensional middle surface model, then, the bolt connection area of the intermediate curved surface is subjected to a geometric expansion operation to generate a first node coupling area for subsequent node coupling operation, wherein the geometric expansion operation is to expand an annular area around the bolt hole. If there are solid members in the connected structure, the geometric expansion operation can be performed on the bolt connection area of the solid members to generate a second node coupling area. For the connected structure with both plate shell members and solid members, the first node coupling area and the second node coupling area are merged to form a complete double-ring annular area to simulate the effect of a gasket; if the connected structure only has plate shell members, then the first node coupling area is the final annular area, in this case, the first node coupling area is a complete double-ring annular area; if the connected structure only has solid members, then the second node coupling area is the final annular area, in this case, the second node coupling area is a complete double-ring annular area.

[0058] To make the skilled in the art further understand the equivalent finite element modeling method of the connecting bolt proposed by the embodiments of the present application, the following will be further described in conjunction with Figures 2-12 .

[0059] As Figure 2 shown, the equivalent finite element modeling method of the connecting bolt can further include the following steps: Step S201, importing the geometric model of the bolt and the connected structure.

[0060] Step S202a, the type between the connected structures is plate shell-plate shell connection.

[0061] Step S202b, the type between the connected structures is plate shell-solid connection.

[0062] Step S202c, the type between the connected structures is plate shell-solid (solid with internal thread) connection.

[0063] Step S202d, the type between the connected structures is solid-solid connection.

[0064] Step S203a, extracting the middle surface of the plate shell structure, and the Washer two rings of the bolt hole edge.

[0065] Step S203b, extracting the middle surface of the plate shell structure, and the Washer two rings of the bolt hole edge of the plate shell and solid structure.

[0066] Step S203c, the Washer two rings of the bolt hole edge.

[0067] Step S204a, the grid is divided by quadrilateral elements.

[0068] Step S204b, the grid is divided by quadrilateral elements and tetrahedral elements.

[0069] Step S204c, the grid is divided by tetrahedral elements.

[0070] Step S205a, the bolt is simulated by beam elements (segmented).

[0071] Step S205b, the bolt is simulated by beam elements (segmented and different region element diameters).

[0072] Step S206, the contact area is simulated by rigid body elements.

[0073] Step S207, it is judged whether the network model is in a fully connected state. If yes, the modeling process is ended, otherwise step S206 is executed.

[0074] The equivalent finite element modeling method of the connecting bolt is further described below for different connection types between the bolt and the connected structure.

[0075] Explanation of the vehicle coordinate system: the vehicle points from the front to the tail as the X-axis positive direction (1 direction), vertically upward as the Z-axis positive direction (3 direction), and the Y-axis positive direction of the vehicle coordinate system is combined with the right-hand screw rule, and the rotation directions around the X, Y and Z axes represent the 4, 5 and 6 directions respectively.

[0076] First step, the geometric model of the bolt and the connected structure is imported by using Hypermesh software, if there is a plate shell structure in the connected structure, the middle surface of the plate shell structure is extracted first.

[0077] Second step, the middle surface is geometrically processed by using Hypermesh software, the bolt hole periphery is Wasered twice, the bolt hole periphery of the solid structure is also Wasered twice, if the nominal diameter of the connecting bolt shank is D, after the geometric processing of the bolt hole periphery is completed, the outer diameter of the Waser is 2.5D, as shown in Figure 3 .

[0078] Third step, the middle surface and the solid structure after geometric processing are meshed by using Hypermesh software, the surface structure is meshed by quadrilateral elements, and the solid structure is meshed by second-order tetrahedral elements.

[0079] Fourth step, when the connected structure is a plate shell structure, as shown in Figure 4 , the bolt connects three layers of plate shell structures. The equivalent simplified model of the bolt connection is as shown in Figure 5Beam element diameter is 2.5D, and the Beam element is divided into at least three sections to accurately simulate the flexibility of the screw. All nodes of the Washer area of the shell structure are slave points of the Rbe2 rigid element, and the nodes of the Beam element in the shell plane are master points of the Rbe2 rigid element. The diameter of the Washer area and the screw diameter are 2.5D to more accurately simulate the connection stiffness of the bolt compression area. If the Washer area and the screw diameter are simulated as D, the connection stiffness is smaller than the actual value. The same applies to the following several connection methods.

[0080] Step 5, when the connected structure is a shell-solid structure, as shown in Figure 6 The bolt connects the shell-solid structure. The equivalent simplified model of the bolt connection is shown in Figure 7 The screw between the shell and the solid is simulated by a Beam element, and the Beam element diameter is 2.5D. To accurately simulate the flexibility of the screw, the Beam element is divided into at least three sections. The screw inside the solid is simulated by a Beam element, and the Beam element diameter is D. To accurately simulate the flexibility of the screw, the Beam element is divided into at least three sections. All nodes of the Washer area of the solid structure are slave points of the Rbe2 rigid element, and the nodes of the Beam element in the Washer plane are master points of the Rbe2 rigid element.

[0081] Step 6, when the connected structure is a solid-solid structure, as shown in Figure 7 The bolt connects the solid-solid structure. The equivalent simplified model of the bolt connection is shown in Figure 8 The screw inside the solid is simulated by a Beam element, and the Beam element diameter is D. To accurately simulate the flexibility of the screw, the Beam element is divided into at least three sections. The screw between the solids is simulated by a Beam element, and the Beam element diameter is 2.5D, which can accurately simulate the connection stiffness and output the connection load between the solids. All nodes of the Washer area of the solid structure are slave points of the Rbe2 rigid element, and the nodes of the Beam element in the Washer plane are master points of the Rbe2 rigid element.

[0082] Step 7, when the connected structure is a shell-solid or solid-solid structure, and the solid structure has internal threads, as shown in Figure 9 The bolt connects the shell-solid structure, and the solid structure has internal threads. The equivalent simplified model of the bolt connection is shown in Figure 10As shown, the screw between the plate shell and the entity is simulated by a Beam element, the diameter of the Beam element is 2.5D, and the Beam element is divided into at least three segments in order to accurately simulate the flexibility of the screw. The screw inside the entity is simulated by a Beam element, the diameter of the Beam element is D, and the Beam element inside the entity is divided into at least three segments in order to accurately simulate the flexibility of the screw. The nodes of the Beam element in the washer area are connected to the slave points of the Rbe2 rigid element, and the nodes of the Beam element in the washer plane are connected to the master points of the Rbe2 rigid element.

[0083] In the eighth step, after the equivalent simplified finite element model of the bolt is established, it is checked whether all the connected structures and the simplified bolt are connected. If not, the Rbe2 element is checked. If all are connected, the modeling is ended.

[0084] According to the equivalent finite element modeling method of the connecting bolt provided in the embodiments of the present application, the geometric model of the current bolt and the geometric models of a plurality of connected structures corresponding to the current bolt are obtained, and the connection type between the connected structures is determined. Based on the connection type between the plurality of connected structures, the geometric model of the current bolt is equivalent to a one-dimensional beam element that meets the preset target diameter condition, wherein the diameter of the beam element section located between adjacent connected structures is set to a first preset diameter length, and the diameter of the beam element section located inside the connected structure is set to a second preset diameter length. An annular area is established around the bolt hole of each connected structure, and all nodes of the annular area are connected to the nodes of the one-dimensional beam element passing through the annular area, thereby generating an equivalent finite element model of the connecting bolt. Thus, the problems of complex finite element modeling of bolt connection, low calculation efficiency, large model size and easy non-convergence in the prior art are solved, so that the modeling and calculation of bolt connection can be efficiently and quickly completed in large-scale complex structure finite element analysis, and the efficiency of engineering design and analysis is significantly improved.

[0085] Next, the equivalent finite element modeling device of the connecting bolt according to the embodiments of the present application is described with reference to the accompanying drawings.

[0086] Figure 12 is a block schematic diagram of the equivalent finite element modeling device of the connecting bolt according to an embodiment of the present application.

[0087] As shown in Figure 12 , the equivalent finite element modeling device 10 of the connecting bolt includes a first processing module 100, a second processing module 200 and a generation module 300.

[0088] The first processing module 100 is configured to acquire a geometric model of a current bolt and geometric models of a plurality of connected structures corresponding to the current bolt, and determine a connection type between the connected structures. The second processing module 200 is configured to equivalently process the geometric model of the current bolt into a one-dimensional beam element satisfying a preset target diameter condition based on the connection type between the plurality of connected structures, wherein a diameter of a beam element section located between adjacent connected structures is set as a first preset diameter length, and a diameter of a beam element section located inside a connected structure is set as a second preset diameter length, the first preset diameter length being greater than the second preset diameter length. The generating module 300 is configured to establish an annular area around a bolt hole of each connected structure, and connect all nodes of the annular area with nodes of the one-dimensional beam element passing through the annular area, to generate an equivalent finite element model of the connecting bolt.

[0089] Optionally, in some embodiments, the generating module 300 is specifically configured to: determine whether there are plate-shell members and / or solid members in the plurality of connected structures; in a case where there are plate-shell members in the plurality of connected structures, performing a middle surface abstraction operation on the plate-shell members to generate an intermediate curved surface, and performing a geometric expansion operation on a bolt connection area of the intermediate curved surface to generate a first node coupling area; and / or, in a case where there are solid members in the plurality of connected structures, performing a geometric expansion operation on a bolt connection area of the solid members to generate a second node coupling area, wherein the first node coupling area and the second node coupling area constitute the annular area.

[0090] Optionally, in some embodiments, the connection type between the plurality of connected structures is plate-shell-plate-shell connection, and the second processing module 200 is specifically configured to: establish a first one-dimensional beam element penetrating all plate-shell members, and set a diameter of the first one-dimensional beam element as the first preset diameter length.

[0091] Optionally, in some embodiments, the connection type between the plurality of connected structures is plate-shell-solid connection, and the second processing module 200 is specifically configured to: establish a second one-dimensional beam element penetrating the plate-shell member and extending into the solid member; set a diameter of a first beam element section located between the plate-shell member and the solid member and a diameter of a second beam element section located inside the plate-shell member as the first preset diameter length, and set a diameter of a third beam element section located inside the solid member as the second preset diameter length.

[0092] Optionally, in some embodiments, the connection type between the plurality of connected structures is a solid-solid connection, and the second processing module 200 is specifically configured to: establish a third one-dimensional beam element that sequentially passes through the first solid member and the second solid member and extends into the second solid member; set the diameter of a fourth beam element section located between the first solid member and the second solid member to a first preset diameter length, and set the diameter of a fifth beam element section located inside the first solid member and the diameter of a sixth beam element section located inside the second solid member to a second preset diameter length.

[0093] Optionally, in some embodiments, the connection type between the plurality of connected structures is a solid-solid connection and there is an internally threaded solid member, and the second processing module 200 is specifically configured to: establish a fourth one-dimensional beam element that passes through the panel member and extends into the internally threaded solid member; set the diameter of a seventh beam element section located between the panel member and the internally threaded solid member and the diameter of an eighth beam element section located inside the panel member to a first preset diameter length, and set the diameter of a ninth beam element section located inside the internally threaded solid member to a second preset diameter length.

[0094] It should be noted that the foregoing explanation of the equivalent finite element modeling method embodiment of the connecting bolt also applies to the equivalent finite element modeling device of the connecting bolt of this embodiment, which will not be described here again.

[0095] The equivalent finite element modeling device of the connecting bolt according to the embodiments of the present application, by acquiring the geometric model of the current bolt and the geometric models of the plurality of connected structures corresponding to the current bolt, and determining the connection type between the connected structures; based on the connection type between the plurality of connected structures, the geometric model of the current bolt is equivalent to a one-dimensional beam element that meets the preset target diameter condition, wherein the diameter of the beam element section located between adjacent connected structures is set to a first preset diameter length, and the diameter of the beam element section located inside the connected structure is set to a second preset diameter length; an annular area is established around the bolt hole of each connected structure, and all nodes of the annular area are connected with the nodes of the one-dimensional beam element passing through the annular area, to generate an equivalent finite element model of the connecting bolt. Thus, the problems of complex bolt connection finite element modeling, low calculation efficiency, large model size and easy to appear non-convergence in the prior art are solved, so that the modeling and calculation of bolt connection can be efficiently and quickly completed in large-scale complex structure finite element analysis, and the efficiency of engineering design and analysis is significantly improved.

[0096] Figure 13A structural schematic diagram of an electronic device is provided in the embodiments of the present application. The electronic device can include The memory 1301, the processor 1302 and the computer program stored in the memory 1301 and executable on the processor 1302.

[0097] The processor 1302 implements the equivalent finite element modeling method of the connecting bolt provided in the above embodiments when executing the program.

[0098] Further, the electronic device further includes The communication interface 1303 is used for communication between the memory 1301 and the processor 1302.

[0099] The memory 1301 is used for storing the computer program executable on the processor 1302.

[0100] The memory 1301 can include a high-speed RAM (Random Access Memory) memory, and can also include a non-volatile memory, for example, at least one disk memory.

[0101] If the memory 1301, the processor 1302 and the communication interface 1303 are independently implemented, the communication interface 1303, the memory 1301 and the processor 1302 can be connected to each other through a bus and complete communication between each other. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the convenience of representation, Figure 13 In the figure, only one thick line is used to represent, but it does not mean that there is only one bus or one type of bus.

[0102] Optionally, in specific implementation, if the memory 1301, the processor 1302 and the communication interface 1303 are integrated on a chip, the memory 1301, the processor 1302 and the communication interface 1303 can complete communication between each other through an internal interface.

[0103] The processor 1302 can be a CPU (Central Processing Unit), or an ASIC (Application Specific Integrated Circuit), or an integrated circuit configured to implement one or more embodiments of the present application.

[0104] The embodiment of the present application further provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor to realize the equivalent finite element modeling method of the connecting bolt.

[0105] In addition, the terms "first", "second", "third", etc. are used only to describe purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly and specifically limited.

[0106] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, the skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0107] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. An equivalent finite element modeling method for connecting bolts, characterized in that, Includes the following steps: Obtain the geometric model of the current bolt and the geometric models of the multiple connected structures corresponding to the current bolt, and determine the connection type between the connected structures; Based on the connection type between the multiple connected structures, the geometric model of the current bolt is equivalently processed into a one-dimensional beam element that satisfies the preset target diameter condition. The diameter of the beam element segment located between adjacent connected structures is set as a first preset diameter length, and the diameter of the beam element segment located inside the connected structure is set as a second preset direct length. The first preset diameter length is greater than the second preset direct length. An annular region is established around the bolt holes of the geometric model of each of the connected structures, and all nodes of the annular region are connected to the nodes of the one-dimensional beam element passing through the annular region to generate an equivalent finite element model of the connecting bolt.

2. The method according to claim 1, characterized in that, An annular region is established around the bolt holes of the geometric model of each of the connected structures, including: Determine whether there are plate / shell components and / or solid components among the multiple connected structures; In the case where the plate and shell components exist in multiple connected structures, a mid-surface abstraction operation is performed on the plate and shell components to generate an intermediate curved surface, and a geometric expansion operation is performed on the bolt connection area of ​​the intermediate curved surface to generate a first node coupling area. And / or, in the case where the solid component exists in multiple connected structures, a geometric expansion operation is performed on the bolt connection area of ​​the solid component to generate a second node coupling area, wherein the first node coupling area and the second node coupling area constitute the annular area.

3. The method according to claim 1, characterized in that, The connection type between the plurality of connected structures is a plate-shell connection. Based on the connection type between the plurality of connected structures, the geometric model of the current bolt is equivalently processed into a one-dimensional beam element that satisfies a preset target diameter condition, including: Establish a first one-dimensional beam element that runs through all the plate and shell components, and set the diameter of the first one-dimensional beam element to the first preset diameter length.

4. The method according to claim 3, characterized in that, The connection type between the plurality of connected structures is a plate-shell-solid connection. Based on the connection type between the plurality of connected structures, the geometric model of the current bolt is equivalently processed into a one-dimensional beam element that satisfies a preset target diameter condition, including: Establish a second one-dimensional beam element that penetrates the plate shell component and extends into the interior of the solid component; The diameters of the first beam unit segment located between the shell component and the solid component, and the second beam unit segment located inside the shell component, are set to the first preset diameter length, and the diameter of the third beam unit segment located inside the solid component is set to the second preset diameter length.

5. The method according to claim 4, characterized in that, The connection type between the plurality of connected structures is a solid-solid connection. Based on the connection type between the plurality of connected structures, the geometric model of the current bolt is equivalent to a one-dimensional beam element that satisfies a preset target diameter condition, including: Construct a third one-dimensional beam element that passes sequentially through the first solid component and the second solid component and extends into the interior of the second solid component; The diameter of the fourth beam unit segment located between the first solid component and the second solid component is set to the first preset diameter length, and the diameters of the fifth beam unit segment located inside the first solid component and the sixth beam unit segment located inside the second solid component are set to the second preset diameter length.

6. The method according to claim 5, characterized in that, The connection type between the plurality of connected structures is a solid-solid connection, and the solid components contain internal threads. Based on the connection type between the plurality of connected structures, the geometric model of the current bolt is equivalently processed into a one-dimensional beam element that satisfies a preset target diameter condition, including: Establish a fourth one-dimensional beam element that penetrates the plate shell component and extends into the interior of the solid component containing the internal threads; The diameters of the seventh beam unit segment located between the shell component and the solid component with the internal thread, and the eighth beam unit segment located inside the shell component, are set to the first preset diameter length, and the diameter of the ninth beam unit segment located inside the solid component with the internal thread is set to the second preset diameter length.

7. An equivalent finite element modeling device for connecting bolts, characterized in that, include: The first processing module is used to obtain the geometric model of the current bolt and the geometric models of multiple connected structures corresponding to the current bolt, and to determine the connection type between the connected structures. The second processing module is used to process the geometric model of the current bolt into a one-dimensional beam element that satisfies a preset target diameter condition based on the connection type between the multiple connected structures. The diameter of the beam element segment located between adjacent connected structures is set as a first preset diameter length, and the diameter of the beam element segment located inside the connected structure is set as a second preset direct length. The first preset diameter length is greater than the second preset direct length. A generation module is used to create an annular region around the bolt holes of the geometric model of each of the connected structures, and connect all nodes of the annular region to the nodes of the one-dimensional beam element passing through the annular region to generate an equivalent finite element model of the connecting bolts.

8. The apparatus according to claim 7, characterized in that, The generation module is specifically used for: Determine whether there are plate / shell components and / or solid components among the multiple connected structures; In the case where the plate and shell components exist in multiple connected structures, a mid-surface abstraction operation is performed on the plate and shell components to generate an intermediate curved surface, and a geometric expansion operation is performed on the bolt connection area of ​​the intermediate curved surface to generate a first node coupling area. And / or, in the case where the solid component exists in multiple connected structures, a geometric expansion operation is performed on the bolt connection area of ​​the solid component to generate a second node coupling area, wherein the first node coupling area and the second node coupling area constitute the annular area.

9. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the equivalent finite element modeling method for connecting bolts as described in any one of claims 1-6.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the equivalent finite element modeling method for connecting bolts as described in any one of claims 1-6.

Images