A method and device for analyzing the strength of rivets on a frame crossbeam

Abstract

The present invention relates to the technical field of rivet strength analysis, and specifically to a method and device for analyzing the strength of rivets on a frame crossbeam. The method for analyzing the strength of rivets on a frame crossbeam comprises the following steps: performing a bending-torsion combined working condition strength analysis on the overall frame model to obtain the axial force of the set rivet and the relative torsion angle at both ends of the crossbeam; establishing a finite element model of the crossbeam and the rivet, analyzing the finite element model based on the axial force and the relative torsion angle, and obtaining the stress distribution of the set rivet. The method can solve the problem in the prior art that if the rivet concerned is modeled, it is equivalent to converting the linear analysis of a large model into a nonlinear analysis of a large model, which will increase the consumption of computing resources, the nonlinear calculation time is very long, and it is difficult to converge.

Description

Technical Field

[0001] The invention relates to the technical field of rivet strength analysis, and in particular to a method and a device for analyzing the strength of a frame crossbeam rivet. Background Art

[0002] As a key component of the frame, the frame crossbeam mainly resists the torsional deformation of the frame during operation, while the rivet is the key fastening connection between the plates of the crossbeam, which has received great attention during the development process. Finite element technology is a good method for strength analysis of crossbeam rivets in the design and development stage. At present, the strength analysis of bolts in the structure is very mature in the industry, but it has not been seen in the strength analysis of frame crossbeam rivets.

[0003] For the rivet strength analysis of the frame crossbeam connecting plate: it is difficult to determine how much tightening force should be applied to the rivet. As is known to all, in the prior art, in the whole frame strength analysis, the rivet is not specifically modeled, but replaced by a beam unit, so the stress distribution of the rivet cannot be obtained.

[0004] However, if the rivets of interest are modeled, it is equivalent to converting the linear analysis of the large model into a nonlinear analysis of the large model, which increases the consumption of computing resources, prolongs the nonlinear calculation time, and also has the problem of difficulty in convergence. Summary of the invention

[0005] In view of the defects existing in the prior art, the purpose of the present invention is to provide a method and device for analyzing the strength of rivets of a frame crossbeam, which can solve the problem in the prior art that if the rivets of concern are modeled, it is equivalent to turning the linear analysis of the large model into a nonlinear analysis of the large model, which will increase the consumption of computing resources, the nonlinear calculation time is very long, and there will also be problems of difficulty in convergence.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0007] In one aspect, the present invention provides a method for analyzing the strength of a frame crossbeam rivet, comprising the following steps:

[0008] Perform bending and torsion combined strength analysis on the overall frame model to obtain the axial force of the set rivets and the relative torsion angles at both ends of the beam;

[0009] A finite element model of the beam and the rivet is established, and the finite element model is analyzed based on the axial force and the relative torsion angle to obtain the stress distribution of the set rivet.

[0010] In some optional solutions, the overall frame model is subjected to a bending-torsion combined strength analysis to obtain the relative torsion angles at both ends of the beam, including:

[0011] Establish the overall model of the frame;

[0012] Perform a combined bending and torsion strength analysis on the overall frame model to obtain the longitudinal displacements of the connecting plates connecting the two ends of the crossbeam to the longitudinal beam.

[0013] According to the displacement of the connecting plates at both ends of the beam in the longitudinal direction, the relative torsion angles at both ends of the beam are determined.

[0014] In some optional schemes, the rivets in the overall frame model adopt beam units, and when the overall frame model is subjected to a bending-torsion combined working condition strength analysis, the axial force of the beam unit corresponding to the set rivet is obtained.

[0015] In some alternative schemes, according to the formula Determine the relative torsion angle θ at both ends of the beam, where d A is the vertical displacement of the first end of the connecting plate at one end of the beam in the longitudinal direction, d B is the vertical displacement of the second end of the connecting plate at one end of the beam in the longitudinal direction, d C is the vertical displacement of the first end of the connecting plate at the other end of the beam in the longitudinal direction, d D is the vertical displacement of the second end of the connecting plate at the other end of the beam in the longitudinal direction, L AB L is the distance between the two ends of the connecting plate at one end of the beam in the longitudinal direction; CD It is the distance between the two ends of the connecting plate at the other end of the beam in the longitudinal direction.

[0016] In some optional solutions, the step of establishing a finite element model of the beam and the rivet, analyzing the finite element model based on the axial force and the relative torsion angle, and obtaining a stress distribution of the set rivet includes:

[0017] Establish finite element model of beam and rivet;

[0018] Setting boundary conditions of a finite element model with the relative torsion angle;

[0019] The axial force is used to set the preload force of the rivet in the finite element model;

[0020] Perform finite element strength analysis on the finite element model to obtain the stress distribution of the set rivets.

[0021] In some optional solutions, when establishing the finite element model of the beam and the rivet, the plate in the local area around the rivet is modeled with hexahedral units according to its actual thickness.

[0022] In some optional solutions, when establishing the finite element model of the beam and the rivet, the shank of the rivet is in surface contact with the plate in the thickness direction and both ends of the rivet are in contact with the plate.

[0023] In some optional solutions, the overall frame model is subjected to a bending-torsion combined strength analysis using Hyperworks.

[0024] In some optional solutions, a finite element model of the beam and the rivet is established, and the finite element model is analyzed based on the axial force and the relative torsion angle using Abaqus.

[0025] In another aspect, the present invention provides a frame crossbeam rivet strength analysis device, comprising the following steps:

[0026] The overall analysis module is used to perform a bending-torsion combined strength analysis on the overall frame model to obtain the axial force of the set rivets and the relative torsion angles at both ends of the beam;

[0027] The local analysis module is used to establish a finite element model of the beam and the rivet, analyze the finite element model based on the axial force and the relative torsion angle, and obtain the stress distribution of the set rivet.

[0028] Compared with the prior art, the advantages of the present invention are: by first performing a bending-torsion combined working condition strength analysis on the overall frame model, the axial force of the set rivet and the relative torsion angle at both ends of the beam are obtained; a finite element model of the beam and the rivet is established, and the finite element model is strength analyzed based on the axial force and relative torsion angle obtained in the overall frame model to obtain the stress distribution of the set rivet. In this solution, the overall frame model is relatively large, and the rivets are replaced by beam units. Linear analysis can be used to improve the analysis efficiency. Only a finite element model of the beam and the rivet is established. The finite element model is much smaller than the overall frame model, and the finite element model can be more finely meshed to perform nonlinear analysis. The finite element model converges well, and the data obtained is more accurate, and the stress distribution of the set rivet can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 Flow chart of a method for analyzing the strength of a frame crossbeam rivet in an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of an overall model of a vehicle frame in an embodiment of the present invention;

[0032] Figure 3 is a schematic diagram of a finite element model of a beam and a rivet of the present invention;

[0033] Figure 4 Flow chart of a vehicle frame crossbeam rivet strength analysis device according to an embodiment of the present invention;

[0034] In the figure: 1. longitudinal beam; 2. cross beam; 3. connecting plate; 4. rivet. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution 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 ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0036] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0037] Figure 1 is a flow chart of a method for analyzing the strength of a frame crossbeam rivet in an embodiment of the present invention; Figure 1 As shown, on the one hand, the present invention provides a method for analyzing the strength of a frame crossbeam rivet, comprising the following steps:

[0038] S1: Perform bending-torsion combined strength analysis on the overall frame model to obtain the axial force of the set rivets and the relative torsion angles at both ends of the beam.

[0039] In this example, the strength analysis of the overall frame model under bending and torsion combined working conditions is performed in the same manner as in the prior art, and the rivets are not specifically modeled, but are replaced by beam elements, and linear analysis is performed. Specifically, Hyperworks performs the strength analysis of the overall frame model under bending and torsion combined working conditions.

[0040] In some optional embodiments, step S1 includes the following steps:

[0041] Figure 2 FIG. 1 is a schematic diagram of the overall model of the vehicle frame in an embodiment of the present invention, as shown in FIG. Figure 2 As shown,

[0042] S11: Establish the overall model of the frame.

[0043] The rivets in the overall frame model adopt beam units. When the overall frame model is subjected to a bending-torsion combined working condition strength analysis, the axial force of the beam unit corresponding to the set rivets is obtained.

[0044] In this example, beam elements are used instead of rivets, and linear analysis can be used to save model simulation analysis time. When performing bending-torsion combined strength analysis on the overall frame model, the axial force of the beam element corresponding to the set rivet is obtained, which can be used as the boundary condition of the subsequent local detailed model, thereby reducing calculation and analysis time and improving design efficiency.

[0045] S12: Perform a combined bending and torsion strength analysis on the overall frame model to obtain the displacements of the connecting plates connecting the two ends of the crossbeam to the longitudinal beam at both ends in the longitudinal direction.

[0046] In this example, the overall model of the vehicle frame includes two longitudinal beams 1 and a cross beam 2 connecting the two longitudinal beams 1. The two ends of the cross beam 2 are connected to the longitudinal beam 1 through a connecting plate 3. The connecting plate 3 and the cross beam 2 are connected through a rivet 4. In the overall model of the vehicle frame, the rivet 4 is replaced by a beam unit. When performing a bending-torsion combined strength analysis on the overall model of the vehicle frame, the displacements of the two ends of the connecting plate 3 in the longitudinal direction are obtained. The displacements of the connecting plate 3 in the longitudinal direction at both ends of the cross beam 2 connected to the longitudinal beam 1 can be used to calculate the relative torsion angles at both ends of the cross beam 2, which can be used as the limiting boundary conditions of the cross beam 2 in the subsequent local detailed model.

[0047] In a specific embodiment, under the combined bending and torsion strength condition of the frame, the axial force of the beam unit corresponding to the rivet is set to 562N. The axial force of the beam unit corresponding to the rivet can simulate the fastening effect of the rivet on the plate.

[0048] S13: Determine the relative torsion angles at both ends of the beam according to the displacements of the connecting plates at both ends of the beam in the longitudinal direction.

[0049] In this example, the relative torsion angle at both ends of the beam 2 can be calculated based on the displacement of the connecting plates at both ends of the beam in the longitudinal direction and the distance between the connecting plates in the longitudinal direction. In other embodiments, other methods can be used to obtain other parameters to calculate the relative torsion angle at both ends of the beam 2, which can also achieve the same effect.

[0050] Specifically, according to the formula Determine the relative torsion angle θ at both ends of the beam, where d A is the vertical displacement of the first end of the connecting plate at one end of the beam in the longitudinal direction, d B is the vertical displacement of the second end of the connecting plate at one end of the beam in the longitudinal direction, d C is the vertical displacement of the first end of the connecting plate at the other end of the beam in the longitudinal direction, d D is the vertical displacement of the second end of the connecting plate at the other end of the beam in the longitudinal direction, L AB L is the distance between the two ends of the connecting plate at one end of the beam in the longitudinal direction; CD It is the distance between the two ends of the connecting plate at the other end of the beam in the longitudinal direction.

[0051] Figure 3 Schematic diagram of the finite element model of the crossbeam and rivet of the present invention; Figure 3 As shown,

[0052] S2: Establish a finite element model of the beam and the rivet, analyze the finite element model based on the axial force and the relative torsion angle, and obtain the stress distribution of the set rivet.

[0053] In this example, the rivet is set as the rivet of interest. A finite element model of the beam and the rivet is established, and the finite element model is analyzed based on the axial force and the relative torsion angle using Abaqus. Specifically, a finite element model of the beam and the rivet is established in Abaqus, and the plate in the local area around the rivet that needs to be studied is modeled with hexahedral units according to its actual thickness, and the contact between the rivet shaft and the surface in the thickness direction of the plate and the contact between the two ends of the rivet and the plate are defined, thereby establishing a finite element model of the beam and the rivet.

[0054] In some optional implementations, step S2 includes the following steps:

[0055] S21: Establish the finite element model of the beam and rivets.

[0056] In some optional embodiments, when establishing the finite element model of the beam and the rivet, the plate in the local area around the rivet is modeled with hexahedral units according to its actual thickness.

[0057] In this example, by setting the plate in the local area around the rivet to be modeled with hexahedral units according to its actual thickness, a more accurate finite element analysis model of the beam and the rivet can be obtained, and more accurate data can be obtained during simulation. In other embodiments, other forms of meshing methods can also be used for modeling, as long as nonlinear finite element simulation can be performed on the established finite element model of the beam and the rivet. In addition, in this solution, only the finite element model of the beam and the rivet is used during modeling, and the model can be analyzed using a nonlinear analysis method to obtain a more accurate simulation result.

[0058] In addition, when establishing the finite element model of the beam and the rivet, the rivet shaft is in surface contact with the plate in the thickness direction, and both ends of the rivet are in contact with the plate.

[0059] In this example, the surface contact between the rivet shaft and the plate in the thickness direction, the way the two ends of the rivet contact the plate, and the axial force of the beam unit corresponding to the rivet obtained in the bending-torsion combined strength analysis of the overall frame model can be used to simulate the fastening effect of the rivet on the plate.

[0060] S22: Setting boundary conditions of the finite element model with the relative torsion angle.

[0061] In step S1, a vehicle frame overall model is established, which includes two longitudinal beams 1 and a cross beam 2 connecting the two longitudinal beams 1, the two ends of the cross beam 2 are connected to the longitudinal beam 1 through a connecting plate 3, and the connecting plate 3 is connected to the cross beam 2 through a rivet 4, and the rivet 4 is replaced by a beam unit in the vehicle frame overall model. The overall frame model is subjected to a bending-torsion combined working condition strength analysis, and the displacements of the two ends of the connecting plate 3 in the longitudinal direction are obtained. The displacements of the connecting plate 3 in the longitudinal direction at the two ends of the cross beam 2 connected to the longitudinal beam 1 can be used to calculate the relative torsion angles at the two ends of the cross beam 2, and the relative torsion angles at the two ends of the cross beam 2 are used as boundary conditions for setting the finite element model.

[0062] S23: setting a pre-tightening force of the rivet in the finite element model according to the axial force.

[0063] In step S1, a vehicle frame overall model is established, which includes two longitudinal beams 1 and a cross beam 2 connecting the two longitudinal beams 1, the two ends of the cross beam 2 are connected to the longitudinal beam 1 through a connecting plate 3, and the connecting plate 3 and the cross beam 2 are connected through a rivet 4, and the rivet 4 is replaced by a beam unit in the vehicle frame overall model. The overall model of the vehicle frame is subjected to a bending-torsion combined working condition strength analysis, and the axial force of the beam unit corresponding to the set rivet is obtained, that is, the axial force of the beam unit corresponding to the concerned rivet, and the axial force of the beam unit corresponding to the concerned rivet is used as the preload force of the set rivet in the finite element model.

[0064] S24: Perform finite element strength analysis on the finite element model to obtain stress distribution of the set rivet.

[0065] In this example, a finite element model of the beam and rivets is established in the nonlinear finite element software Abaqus. When the finite element strength analysis is performed on the finite element model, the finite element model only includes the beam and rivets. The scale of this local model is much smaller than the entire frame model. The beam and rivet can be finely meshed, and the nonlinear analysis is easier to converge, and the stress distribution of the set rivets can be obtained.

[0066] In the strength analysis of the crossbeam rivets of a certain vehicle model, this method was applied to analyze and verify the strength difference between the three-rivet structure and the four-rivet structure. The maximum principal stress of the three-rivet structure is 469.8Mpa, and the maximum principal stress of the four-rivet structure is 268.5Mpa.

[0067] This solution first performs a strength analysis of the overall frame model under a combined bending and torsion condition to obtain the axial force of the set rivet and the relative torsion angle at both ends of the beam; a finite element model of the beam and rivet is established, and the finite element model is strength analyzed based on the axial force and relative torsion angle obtained from the overall frame model to obtain the stress distribution of the set rivet. In this solution, the overall frame model is relatively large, and the rivets are replaced by beam units. Linear analysis can be used to improve the analysis efficiency. Only a finite element model of the beam and rivets is established. The finite element model is much smaller than the overall frame model, and the finite element model can be more finely meshed to perform nonlinear analysis. The finite element model converges well, and the data obtained is more accurate, and the stress distribution of the set rivet can be obtained.

[0068] Figure 4 FIG. 1 is a flow chart of a vehicle frame crossbeam rivet strength analysis device according to an embodiment of the present invention. Figure 4 As shown, on the other hand, the present invention also provides a rivet strength analysis device for a frame crossbeam, comprising the following steps: an overall analysis module and a local analysis module. The overall analysis module is used to perform a bending-torsion combined working condition strength analysis on the overall model of the frame, and obtain the axial force of the set rivet and the relative torsion angle at both ends of the crossbeam; the local analysis module is used to establish a finite element model of the crossbeam and the rivet, and analyze the finite element model based on the axial force and the relative torsion angle to obtain the stress distribution of the set rivet.

[0069] The overall analysis module is also used for:

[0070] Establish the overall model of the frame.

[0071] The overall frame model is subjected to a combined bending and torsion strength analysis to obtain the displacements of the connecting plates at both ends of the crossbeam and the longitudinal beam.

[0072] According to the displacement of the connecting plates at both ends of the beam in the longitudinal direction, the relative torsion angles at both ends of the beam are determined.

[0073] The rivets in the overall frame model adopt beam units. When the overall frame model is subjected to a bending-torsion combined working condition strength analysis, the axial force of the beam unit corresponding to the set rivets is obtained.

[0074] The overall frame model uses beam units to replace rivets, and linear analysis can be used to save model simulation analysis time. When performing bending-torsion combined strength analysis on the overall frame model, the axial force of the beam unit corresponding to the set rivet is obtained, which can be used as the boundary condition of the subsequent local detailed model, thereby reducing calculation and analysis time and improving design efficiency.

[0075] The overall model of the vehicle frame includes two longitudinal beams 1 and a cross beam 2 connecting the two longitudinal beams 1. The two ends of the cross beam 2 are connected to the longitudinal beam 1 through a connecting plate 3. The connecting plate 3 and the cross beam 2 are connected through a rivet 4. In the overall model of the vehicle frame, the rivet 4 is replaced by a beam unit. When the overall model of the vehicle frame is subjected to a strength analysis of the bending-torsion combined working condition, the displacements of the two ends of the connecting plate 3 in the longitudinal direction are obtained. The displacements of the connecting plate 3 in the longitudinal direction at both ends of the cross beam 2 connected to the longitudinal beam 1 can be used to calculate the relative torsion angles at both ends of the cross beam 2, which can be used as the limiting boundary conditions of the cross beam 2 in the subsequent local detailed model.

[0076] Under the combined bending and torsion strength condition of the frame, the axial force of the beam unit corresponding to the rivet is set to 562N. The axial force of the beam unit corresponding to the rivet can be used to simulate the fastening effect of the rivet on the plate.

[0077] According to the displacement of the connecting plates at both ends of the beam in the longitudinal direction and the distance between the connecting plates at both ends in the longitudinal direction, the relative torsion angle at both ends of the beam 2 can be calculated. In other embodiments, other methods can be used to obtain other parameters to calculate the relative torsion angle at both ends of the beam 2, which can also achieve the same effect.

[0078] According to the formula Determine the relative torsion angle θ at both ends of the beam, where d A is the vertical displacement of the first end of the connecting plate at one end of the beam in the longitudinal direction, d B is the vertical displacement of the second end of the connecting plate at one end of the beam in the longitudinal direction, d C is the vertical displacement of the first end of the connecting plate at the other end of the beam in the longitudinal direction, d D is the vertical displacement of the second end of the connecting plate at the other end of the beam in the longitudinal direction, L AB L is the distance between the two ends of the connecting plate at one end of the beam in the longitudinal direction; CD It is the distance between the two ends of the connecting plate at the other end of the beam in the longitudinal direction.

[0079] The local analysis module is also specifically used for:

[0080] Establish the finite element model of the beam and rivets.

[0081] The boundary conditions of the finite element model are set with the relative torsion angle.

[0082] The preload force of the rivet is set in the finite element model using the axial force.

[0083] Perform finite element strength analysis on the finite element model to obtain the stress distribution of the set rivets.

[0084] When establishing the finite element model of the beam and the rivet, the plate in the local area around the rivet is modeled with hexahedral units according to its actual thickness.

[0085] By setting the plate in the local area around the rivet to be modeled with hexahedral units according to its actual thickness, a more accurate finite element analysis model of the beam and the rivet can be obtained, and more accurate data can be obtained during simulation. In other embodiments, other forms of meshing methods can also be used for modeling, as long as nonlinear finite element simulation can be performed on the established finite element model of the beam and the rivet. In addition, in this solution, only the finite element model of the beam and the rivet is used during modeling, and the model can be analyzed using a nonlinear analysis method to obtain a more accurate simulation result.

[0086] In addition, when establishing the finite element model of the beam and the rivet, the rivet shaft is in surface contact with the plate in the thickness direction, and both ends of the rivet are in contact with the plate.

[0087] The surface contact between the rivet shaft and the plate in the thickness direction and the way the two ends of the rivet contact the plate, as well as the axial force of the beam unit corresponding to the rivet obtained in the bending-torsion combined strength analysis of the overall frame model, can be used to simulate the fastening effect of the rivet on the plate.

[0088] By establishing a vehicle frame overall model including two longitudinal beams 1 and a cross beam 2 connecting the two longitudinal beams 1, the two ends of the cross beam 2 are connected to the longitudinal beam 1 through a connecting plate 3, and the connecting plate 3 and the cross beam 2 are connected through a rivet 4, and the rivet 4 is replaced by a beam unit in the vehicle frame overall model. The overall frame model is subjected to a bending-torsion combined working condition strength analysis, and the displacements of the two ends of the connecting plate 3 in the longitudinal direction are obtained. The displacements of the connecting plate 3 in the longitudinal direction at both ends of the cross beam 2 and the longitudinal beam 1 can be used to calculate the relative torsion angles at both ends of the cross beam 2, and the relative torsion angles at both ends of the cross beam 2 are used as boundary conditions for setting the finite element model.

[0089] By establishing a vehicle frame overall model including two longitudinal beams 1 and a cross beam 2 connecting the two longitudinal beams 1, the two ends of the cross beam 2 are connected to the longitudinal beam 1 through a connecting plate 3, and the connecting plate 3 and the cross beam 2 are connected through a rivet 4, and the rivet 4 is replaced by a beam unit in the vehicle frame overall model. The overall frame model is subjected to a bending-torsion combined working condition strength analysis, and the axial force of the beam unit corresponding to the set rivet is obtained, that is, the axial force of the beam unit corresponding to the concerned rivet, and the axial force of the beam unit corresponding to the concerned rivet is used as the preload force of the set rivet in the finite element model.

[0090] A finite element model of the beam and rivets is established in the nonlinear finite element software Abaqus. When the finite element strength analysis is performed on the finite element model, the finite element model only includes the beam and rivets. The scale of this local model is much smaller than the entire frame model. The beam and rivet can be finely meshed, and the nonlinear analysis is easier to converge, and the stress distribution of the set rivets can be obtained.

[0091] In summary, by first performing a bending-torsion combined strength analysis on the overall frame model, the axial force of the set rivet and the relative torsion angle at both ends of the beam are obtained; a finite element model of the beam and the rivet is established, and the finite element model is strength analyzed based on the axial force and relative torsion angle obtained in the overall frame model to obtain the stress distribution of the set rivet. In this solution, the overall frame model is relatively large, and the rivets are replaced by beam units. Linear analysis can be used to improve the analysis efficiency. Only a finite element model of the beam and the rivet is established. The finite element model is much smaller than the overall frame model, and the finite element model can be more finely meshed, so as to perform nonlinear analysis. The finite element model converges well, and the data obtained is more accurate, and the stress distribution of the set rivet can be obtained.

[0092] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0093] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0094] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for analyzing the strength of a frame crossbeam rivet, characterized in that: The following steps are involved: Perform bending and torsion combined strength analysis on the overall frame model to obtain the axial force of the set rivets and the relative torsion angles at both ends of the beam; The rivets in the overall frame model adopt beam units, and when the overall frame model is subjected to a bending-torsion combined working condition strength analysis, the axial force of the beam unit corresponding to the set rivets is obtained; The bending-torsion combined working condition strength analysis is performed on the overall frame model to obtain the relative torsion angles at both ends of the beam, including: Establish the overall model of the frame; Perform a combined bending and torsion strength analysis on the overall frame model to obtain the longitudinal displacements of the connecting plates connecting the two ends of the crossbeam to the longitudinal beam. According to the displacement of the connecting plates at both ends of the beam in the longitudinal direction, the relative torsion angles at both ends of the beam are determined; According to the formula Determine the relative torsion angle θ at both ends of the beam, where d A is the vertical displacement of the first end of the connecting plate at one end of the beam in the longitudinal direction, d B is the vertical displacement of the second end of the connecting plate at one end of the beam in the longitudinal direction, d C is the vertical displacement of the first end of the connecting plate at the other end of the beam in the longitudinal direction, d D is the vertical displacement of the second end of the connecting plate at the other end of the beam in the longitudinal direction, L AB L is the distance between the two ends of the connecting plate at one end of the beam in the longitudinal direction; CD is the distance between the two ends of the connecting plate at the other end of the beam in the longitudinal direction; A finite element model of the beam and the rivet is established, and the finite element model is analyzed based on the axial force and the relative torsion angle to obtain the stress distribution of the set rivet.

2. The frame crossbeam rivet strength analysis method according to claim 1, characterized in that: The step of establishing a finite element model of the beam and the rivet, analyzing the finite element model based on the axial force and the relative torsion angle, and obtaining the stress distribution of the set rivet includes: Establish finite element model of beam and rivet; Setting boundary conditions of a finite element model with the relative torsion angle; The axial force is used to set the preload force of the rivet in the finite element model; Perform finite element strength analysis on the finite element model to obtain the stress distribution of the set rivets.

3. The frame crossbeam rivet strength analysis method according to claim 1, characterized in that: When establishing the finite element model of the beam and the rivet, the plate in the local area around the rivet is modeled with hexahedral units according to its actual thickness.

4. The frame crossbeam rivet strength analysis method according to claim 1, characterized in that: When establishing the finite element model of the beam and the rivet, the rivet shaft is in surface contact with the plate in the thickness direction, and the two ends of the rivet are in contact with the plate.

5. The frame crossbeam rivet strength analysis method according to claim 1, characterized in that: The overall frame model is subjected to combined bending and torsion strength analysis using Hyperworks.

6. The frame crossbeam rivet strength analysis method according to claim 1, characterized in that: A finite element model of the beam and the rivet is established, and the finite element model is analyzed based on the axial force and the relative torsion angle using Abaqus.

7. A frame crossbeam rivet strength analysis device, characterized in that: The following steps are involved: The overall analysis module is used to perform a bending-torsion combined working condition strength analysis on the overall model of the frame, and obtain the axial force of the set rivet and the relative torsion angle at both ends of the beam; the rivets in the overall model of the frame adopt beam units, and when the bending-torsion combined working condition strength analysis is performed on the overall model of the frame, the axial force of the beam unit corresponding to the set rivet is obtained; the bending-torsion combined working condition strength analysis is performed on the overall model of the frame, and the relative torsion angle at both ends of the beam is obtained, including: establishing the overall model of the frame; performing a bending-torsion combined working condition strength analysis on the overall model of the frame, and obtaining the displacement of the connecting plates connecting the two ends of the beam and the longitudinal beam at both ends in the longitudinal direction; determining the relative torsion angle at both ends of the beam according to the displacement of the connecting plates at both ends of the beam in the longitudinal direction; according to the formula Determine the relative torsion angle θ at both ends of the beam, where d A is the vertical displacement of the first end of the connecting plate at one end of the beam in the longitudinal direction, d B is the vertical displacement of the second end of the connecting plate at one end of the beam in the longitudinal direction, d C is the vertical displacement of the first end of the connecting plate at the other end of the beam in the longitudinal direction, d D is the vertical displacement of the second end of the connecting plate at the other end of the beam in the longitudinal direction, L AB L is the distance between the two ends of the connecting plate at one end of the beam in the longitudinal direction; CD is the distance between the two ends of the connecting plate at the other end of the beam in the longitudinal direction; The local analysis module is used to establish a finite element model of the beam and the rivet, analyze the finite element model based on the axial force and the relative torsion angle, and obtain the stress distribution of the set rivet.

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