A strength analysis method for small trucks without front fender cargo box

Abstract

The present application relates to a strength analysis method for a small truck without a front fender cargo box, comprising: establishing a simulation model of a small truck without a front fender cargo box, establishing a simulation model in which the cargo box side panels are connected to the cab rear panel using a front lock hook model, and the cargo box side panels are connected to the cargo box rear panel using a rear lock hook model; then adjusting the degrees of freedom of the front lock hook model and the rear lock hook model according to different simulation conditions; finally, for different simulation conditions, conducting simulation tests on the small truck simulation model established based on the constrained degrees of freedom of the front lock hook model and the rear lock hook model to obtain simulation results, and characterizing the structural strength of the small truck simulation model according to the simulation results. The present application simplifies the establishment of finite element models of the front lock hook model and the rear lock hook model through different simulation conditions, optimizes the connection method of the front lock hook model and the rear lock hook model according to different conditions, and further ensures the accuracy of the strength analysis of the entire vehicle.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle body strength simulation analysis, and in particular to a strength analysis method for a small truck without a front fender cargo box. Background Art

[0002] The structural strength of a vehicle is primarily determined by the strength of its body. The body-in-white (BIW) bears the weight and acceleration of the vehicle under various operating conditions, including starting from a standstill, braking, turning left and right, and vertical impact. The forces acting on each BIW component vary in direction and magnitude under these conditions. To ensure that the BIW does not crack or deform during normal driving, strength simulation calculations must be performed during BIW design.

[0003] The conventional method for strength simulation analysis of the body-in-white (BIW) structure of small trucks relies on applying G-loads for impact, braking, and steering conditions. While this method is highly efficient, it suffers from large simulation errors and fails to accurately represent critical areas. Another approach involves collecting road test profiles, performing virtual iterations, and extracting loads at external points. This extracted load is then used to perform structural strength simulation analysis of the BIW. While this method offers high accuracy, it suffers from a long cycle time and low efficiency. Summary of the Invention

[0004] An embodiment of the present application provides a strength analysis method for a small truck without a front fender cargo box to solve the problem in related technologies that the strength simulation analysis of the body-in-white structure of a small truck has large errors and cannot truly reflect dangerous parts.

[0005] The present application provides a method for analyzing the strength of a small truck without a front fender cargo box, including:

[0006] Establish a simulation model of a small truck without a front fender and cargo box. In the simulation model, the cargo box side panels are connected to the cab rear panel using a front lock hook model, and the cargo box side panels are connected to the cargo box rear panel using a rear lock hook model.

[0007] According to different simulation conditions, the degrees of freedom of the front lock hook model to constrain the cargo box side panels and the cab rear panel are adjusted, and the degrees of freedom of the rear lock hook model to constrain the cargo box side panels and the cargo box rear panel are adjusted;

[0008] For different simulation working conditions, simulation tests are carried out on a small truck simulation model established based on the constrained degrees of freedom of the front lock hook model and the rear lock hook model to obtain simulation results. The structural strength of the small truck simulation model is characterized based on the simulation results.

[0009] In some embodiments, under a simulated vertical impact condition, the small truck simulation model uses an RBE2 unit to adjust the front lock hook model to constrain the degrees of freedom of the cargo box side panel and the cab rear panel, so that the kinematic joints of the cargo box side panel and the cab rear panel release the degrees of freedom of Z-axis movement, Z-axis rotation, and X-axis movement;

[0010] The RBE2 unit is used to adjust the rear lock hook model to constrain the degrees of freedom of the cargo box side panel and the cargo box rear panel, so that the kinematic joints of the cargo box side panel and the cargo box rear panel release the degrees of freedom of Z-axis movement and Z-axis rotation.

[0011] In some embodiments, the small truck simulation model uses the RBE2 unit to adjust the front lock hook model to constrain the degrees of freedom of the cargo box side panel and the cab rear panel under the braking simulation condition, so that the kinematic joints of the cargo box side panel and the cab rear panel release the degrees of freedom of Z-axis movement, Z-axis rotation, and X-axis movement;

[0012] The RBE2 unit is used to adjust the rear lock hook model to constrain the degrees of freedom of the cargo box side panel and the cargo box rear panel, so that the kinematic joints of the cargo box side panel and the cargo box rear panel release the degrees of freedom of Z-axis movement and Z-axis rotation.

[0013] In some embodiments, the small truck simulation model uses the RBE2 unit to adjust the front lock hook model to constrain the degrees of freedom of the cargo box side panel and the cab rear panel under the simulation working condition of turning, so that the kinematic joints of the cargo box side panel and the cab rear panel release the degrees of freedom of Z-axis movement and Z-axis rotation;

[0014] The RBE2 unit is used to adjust the rear lock hook model to constrain the degrees of freedom of the cargo box side panel and the cargo box rear panel, so that the kinematic joints of the cargo box side panel and the cargo box rear panel release the degrees of freedom of Z-axis movement and Z-axis rotation.

[0015] In some embodiments: the method also includes determining whether the simulation results are reasonable, the simulation results including stress thresholds and displacement thresholds. If so, the simulation results are output; if not, the front lock hook model is readjusted to constrain the degrees of freedom of the cargo box side panel and the cab rear panel, and the rear lock hook model is adjusted to constrain the degrees of freedom of the cargo box side panel and the cargo box rear panel, and then the simulation is performed again.

[0016] In some embodiments: the front lock hook model includes a rear panel bolt connection bracket connected to the cab rear panel bolt, and a side panel connection bracket connected to the cargo box side panel bolt;

[0017] The overlapping bend of the rear panel bolt connection bracket and the overlapping notch of the side panel baffle connection bracket are used as a kinematic pair through the RBE2 unit.

[0018] In some embodiments: the rear lock hook model includes a side panel welding bracket welded to the cargo box side panel, and a rear panel connecting bracket bolted to the cargo box rear panel;

[0019] The overlapping bend of the side panel welding bracket and the overlapping notch of the rear panel connecting bracket are used as a kinematic pair through the RBE2 unit.

[0020] In some embodiments: the small truck simulation model includes a body-in-white, and a front suspension mounting point and a rear suspension mounting point connected to the body-in-white;

[0021] During the simulation test, the maximum acceleration of each working condition is obtained by collecting the road load spectrum of the test site. The front and rear suspension mounting points are loaded according to the maximum acceleration of each working condition to output stress and torque.

[0022] In some embodiments: the front suspension mounting point includes a front suspension strut upper mounting point for mounting a front McPherson suspension simulation model, a front lower suspension arm front mounting point, and a rear lower suspension arm rear mounting point; the rear suspension mounting point includes a rear leaf spring front mounting point, a rear suspension limiter mounting point, and a rear leaf spring rear mounting point of a rear leaf spring suspension simulation model.

[0023] In some embodiments: after the simulation test, the simulation results are statically analyzed using an inertia release method.

[0024] The beneficial effects of the technical solution provided by this application include:

[0025] An embodiment of the present application provides a strength analysis method for a small truck without a front fender cargo box. The strength analysis method for a small truck without a front fender cargo box of the present application first establishes a simulation model of a small truck without a front fender cargo box, and establishes a simulation model in which the cargo box side panels are connected to the cab rear panel by a front locking hook model, and the cargo box side panels are connected to the cargo box rear panel by a rear locking hook model; then, according to different simulation working conditions, the front locking hook model is adjusted to constrain the degrees of freedom of the cargo box side panels and the cab rear panel, and the rear locking hook model is adjusted to constrain the degrees of freedom of the cargo box side panels and the cargo box rear panel; finally, for different simulation working conditions, a simulation test is carried out on the small truck simulation model established based on the constrained degrees of freedom of the front locking hook model and the rear locking hook model to obtain simulation results, and the structural strength of the small truck simulation model is characterized according to the simulation results.

[0026] Therefore, before conducting a body strength analysis on a small truck without a front fender cargo box, the present application adjusts the front lock hook model to constrain the degrees of freedom of the cargo box side panels and the cab rear panel, and adjusts the rear lock hook model to constrain the degrees of freedom of the cargo box side panels and the cargo box rear panel, based on the body structural characteristics of the small truck without a front fender cargo box and according to different simulation working conditions. Under different simulation working conditions, the kinematic pairs of the front lock hook model change with different working conditions, while the kinematic pairs of the rear lock hook model do not change with different working conditions. Therefore, the present application simplifies the establishment of finite element models of the front lock hook model and the rear lock hook model through different simulation working conditions, utilizes the deformation trend of the entire vehicle, and optimizes the connection method of the front lock hook model and the rear lock hook model for different working conditions, further ensuring the accuracy of the strength analysis of the entire vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. 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 any creative work.

[0028] Figure 1 A flow chart of a method according to an embodiment of the present application;

[0029] Figure 2 This is a structural schematic diagram of a simulation model of a small truck without a front fender cargo box from a first perspective of an embodiment of the present application;

[0030] Figure 3 This is a structural schematic diagram of a small truck simulation model without a front fender cargo box from a second perspective of an embodiment of the present application;

[0031] Figure 4 This is a structural diagram of the front lock hook model of an embodiment of the present application;

[0032] Figure 5 This is a structural diagram of the rear lock hook model of an embodiment of the present application;

[0033] Figure 6 This is a schematic structural diagram of a small truck simulation model without a front fender cargo box according to an embodiment of the present application after vertical impact simulation.

[0034] Reference numerals:

[0035] 1. Front locking hook model; 2. Cab rear panel; 3. Cargo box side panel; 4. Rear locking hook model; 5. Cargo box rear panel; 6. Front suspension sliding column upper mounting point; 7. Front suspension lower arm front mounting point; 8. Front suspension lower arm rear mounting point; 9. Rear suspension leaf spring front mounting point; 10. Rear suspension limiter mounting point; 11. Rear suspension leaf spring rear mounting point; 12. Rear panel bolt connection bracket; 13. Side panel connection bracket; 14. Side panel welding bracket; 15. Rear panel connection bracket; 16. Vehicle chassis. DETAILED DESCRIPTION

[0036] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0037] An embodiment of the present application provides a strength analysis method for a small truck without a front fender cargo box, which can solve the problem in related technologies that the strength simulation analysis of the body-in-white structure of small trucks has large errors and cannot truly reflect dangerous parts.

[0038] See also Figure 1 and Figure 2 As shown, the embodiment of the present application provides a strength analysis method for a small truck without a front fender cargo box, comprising:

[0039] Step 101: Establish a simulation model of a small truck without a front fender and cargo box. In the simulation model, the cargo box side fender 3 is connected to the cab rear fender 2 using a front lock hook model 1, and the cargo box side fender 3 is connected to the cargo box rear fender 5 using a rear lock hook model 4.

[0040] Step 102: According to different simulation working conditions, adjust the degrees of freedom of the front lock hook model 1 to constrain the cargo box side panel 3 and the cab rear panel 2, and adjust the degrees of freedom of the rear lock hook model 4 to constrain the cargo box side panel 3 and the cargo box rear panel 5.

[0041] Step 103 : For different simulation working conditions, a simulation test is performed on a small truck simulation model established based on the constrained degrees of freedom of the front hook model 1 and the rear hook model 4 to obtain simulation results, and the structural strength of the small truck simulation model is characterized according to the simulation results.

[0042] Step 104: determine whether the simulation results are reasonable, wherein the simulation results include a stress threshold and a displacement threshold.

[0043] Step 105: If yes, output the simulation results.

[0044] Step 106: If not, readjust the front hook model to constrain the degrees of freedom of the cargo box side panels and the cab rear panel, and adjust the rear hook model to constrain the degrees of freedom of the cargo box side panels and the cargo box rear panel, and then perform simulation again.

[0045] Before conducting a body strength simulation analysis of a small truck without a front fender cargo box, the embodiment of the present application adjusts the front lock hook model 1 to constrain the degrees of freedom of the cargo box side panel 3 and the cab rear panel 2, and adjusts the rear lock hook model 4 to constrain the degrees of freedom of the cargo box side panel 3 and the cargo box rear panel 5, based on the body structure characteristics of the small truck without a front fender cargo box and according to different simulation working conditions.

[0046] The kinematic pairs of the front hook model 1 vary across different simulation conditions. Specifically, the six degrees of freedom of the front hook model 1 are set differently under different simulation conditions, with some constrained and others released. The kinematic pairs of the rear hook model 4 remain unchanged across different simulation conditions. Specifically, the states of the six degrees of freedom of the lower hook model 4 remain unchanged after the simulation conditions are changed.

[0047] Therefore, this application simplifies the establishment of finite element models of the front lock hook model 1 and the rear lock hook model 4 through different simulation working conditions, utilizes the deformation trend of the whole vehicle, and optimizes the connection mode (six degrees of freedom) of the front lock hook model 1 and the rear lock hook model 4 according to different working conditions, so as to further ensure the accuracy of the strength analysis of the whole vehicle.

[0048] The six degrees of freedom (DOF) refer to the movement of an object in three-dimensional space. They include: 1. Translation along the X-axis; 2. Translation along the Y-axis; 3. Translation along the Z-axis; 4. Rotation about the X-axis; 5. Rotation about the Y-axis; and 6. Rotation about the Z-axis. Together, these six degrees of freedom define an object's position and orientation in space.

[0049] In some alternative embodiments: See Figures 4 to 6 As shown, an embodiment of the present application provides a strength analysis method for a small truck without a front fender cargo box. In this method, when the small truck simulation model is under the simulation condition of vertical impact, the RBE2 unit is used to adjust the front lock hook model 1 to constrain the degrees of freedom of the cargo box side panel 3 and the cab rear panel 2, so that the kinematic pair of the cargo box side panel 3 and the cab rear panel 2 releases the three degrees of freedom of Z-axis movement, Z-axis rotation and X-axis movement.

[0050] The RBE2 unit is used to adjust the rear lock hook model 4 to constrain the degrees of freedom of the cargo box side panel 3 and the cargo box rear panel 5, so that the kinematic pairs of the cargo box side panel 3 and the cargo box rear panel 5 release the two degrees of freedom of Z-axis movement and Z-axis rotation.

[0051] The front lock hook model 1 and the rear lock hook model 4 of the embodiment of the present application are mainly composed of two end brackets and spring rings. The present application simplifies the modeling and only establishes the digital model of the two end brackets. The spring rings are simulated by establishing a rotation pair between the main nodes of the RBE2 units tied at both ends, so as to realize the function of the front lock hook model 1 and the rear lock hook model 4 to lock the side panels of the cargo box.

[0052] The master node, also known as an independent node, has its degrees of freedom determined by the degrees of freedom of the slave nodes. In the RBE2 element, the master node's degrees of freedom default to six degrees of freedom: translation and rotation. The RBE2 element is a rigid constraint between multiple nodes, consisting of a master node (with six degrees of freedom by default) and multiple slave nodes (with selectable degrees of freedom).

[0053] The RBE2 element can be simply understood as multiple nodes rigidly welded to one another, resulting in infinite stiffness in the welded sections. Once the RBE2 element is established, there is no relative displacement between the slave nodes, and the elements between the nodes are free of deformation, which improves the overall stiffness of the structure.

[0054] In the embodiment of the present application, under the simulation working condition of vertical impact of a simulation model of a small truck without a front fender cargo box, in order to truly simulate the deformation and stress of the small truck without a front fender cargo box under vertical impact, the three degrees of freedom of Z-axis movement, Z-axis rotation and X-axis movement of the front lock hook model 1 are released, and the two degrees of freedom of Z-axis movement and Z-axis rotation of the rear lock hook model 4 are released.

[0055] When a vertical impact is applied to a simulated small truck model without a front fender and cargo box, the entire vehicle will dent the cab rear panel 2, resulting in excessive X-axis deformation of the front hook 1. When the front hook model 1 is only released for Z-axis movement and rotation, the stress value of the front hook model 1 is much greater than that of the actual vehicle. Therefore, it is necessary to release X-axis movement while releasing Z-axis movement and rotation to direct the vertical impact to the chassis 16. This prevents the vertical impact from being dispersed to the front hook model 1, thereby reducing the vertical impact force on the chassis 16.

[0056] In some alternative embodiments: See Figures 4 to 6 As shown, an embodiment of the present application provides a strength analysis method for a small truck without a front fender cargo box. In this method, under the simulation condition of braking, the small truck simulation model uses the RBE2 unit to adjust the front lock hook model 1 to constrain the degrees of freedom of the cargo box side panel and the cab rear panel, so that the kinematic pair of the cargo box side panel 3 and the cab rear panel 2 releases the three degrees of freedom of Z-axis movement, Z-axis rotation and X-axis movement.

[0057] The RBE2 unit is used to adjust the rear lock hook model 4 to constrain the degrees of freedom of the cargo box side panel 3 and the cargo box rear panel 5, so that the kinematic pairs of the cargo box side panel 3 and the cargo box rear panel 5 release the two degrees of freedom of Z-axis movement and Z-axis rotation.

[0058] The front lock hook model 1 and the rear lock hook model 4 of the embodiment of the present application are mainly composed of two end brackets and spring rings. The present application simplifies the modeling and only establishes the digital model of the two end brackets. The spring rings are simulated by establishing a rotation pair between the main nodes of the RBE2 units tied at both ends, so as to realize the function of the front lock hook model 1 and the rear lock hook model 4 to lock the side panels of the cargo box.

[0059] The master node, also known as an independent node, has its degrees of freedom determined by the degrees of freedom of the slave nodes. In the RBE2 element, the master node's degrees of freedom default to six degrees of freedom: translation and rotation. The RBE2 element is a rigid constraint between multiple nodes, consisting of a master node (with six degrees of freedom by default) and multiple slave nodes (with selectable degrees of freedom).

[0060] The RBE2 element can be simply understood as multiple nodes rigidly welded to one another, resulting in infinite stiffness in the welded sections. Once the RBE2 element is established, there is no relative displacement between the slave nodes, and the elements between the nodes are free of deformation, which improves the overall stiffness of the structure.

[0061] In the embodiment of the present application, under the simulation condition of braking of the simulation model of a small truck without a front fender cargo box, in order to truly simulate the deformation and stress of the small truck without a front fender cargo box under braking, the three degrees of freedom of Z-axis movement, Z-axis rotation and X-axis movement of the front lock hook model 1 are released, and the two degrees of freedom of Z-axis movement and Z-axis rotation of the rear lock hook model 4 are released.

[0062] During braking simulations on a small truck model without a front fender and cargo box, the entire vehicle dents the cab rear panel 2, resulting in excessive X-axis deformation of the front hook 1. When the front hook model 1 is only released for Z-axis movement and rotation, the stress values ​​in the front hook model 1 are significantly greater than those in the actual vehicle. Therefore, releasing both Z-axis movement and rotation also requires releasing X-axis movement to direct the braking impact onto the chassis 16. This prevents the braking impact from being dispersed to the front hook model 1, which in turn reduces the braking force on the chassis 16.

[0063] In some alternative embodiments: See Figures 4 to 6As shown, the embodiment of the present application provides a strength analysis method for a small truck without a front fender cargo box. In this method, the small truck simulation model uses the RBE2 unit to adjust the front lock hook model 1 to constrain the degrees of freedom of the cargo box side panel 3 and the cab rear panel 2 under the simulation working condition of steering, so that the kinematic joints of the cargo box side panel 3 and the cab rear panel 2 release the two degrees of freedom of Z-axis movement and Z-axis rotation;

[0064] The RBE2 unit is used to adjust the rear hook model 4 to constrain the degrees of freedom of the cargo box side panels 3 and the cargo box rear panel 5, so that the kinematic joints of the cargo box side panels 3 and the cargo box rear panel 5 release both Z-axis translation and Z-axis rotation degrees of freedom. In the steering simulation of the present embodiment, the steering kinematic joints of the front hook model 1 are connected in the same manner as the rear hook model 4, both releasing both Z-axis translation and Z-axis rotation degrees of freedom.

[0065] In some alternative embodiments: See Figure 4 and Figure 5 As shown, an embodiment of the present application provides a strength analysis method for a small truck without a front fender and cargo box. In this method, a front hook model 1 includes a rear panel bolt connection bracket 12 bolted to the cab rear panel 2, and a side panel connection bracket 13 bolted to the cargo box side panel 3. The overlapping bend of the rear panel bolt connection bracket 12 and the overlapping notch of the side panel connection bracket 13 are connected as a kinematic pair using RBE2 units.

[0066] The rear latch hook model 4 includes a side panel welding bracket 14 welded to the cargo box side panel 3 and a rear panel connecting bracket 15 bolted to the cargo box rear panel 5. The overlapping bend of the side panel welding bracket 14 and the overlapping notch of the rear panel connecting bracket 15 form a kinematic pair through the RBE2 unit.

[0067] The front lock hook model 1 and the rear lock hook model 4 of the embodiment of the present application are mainly composed of two end brackets and spring rings. The present application simplifies the modeling and only establishes the digital model of the two end brackets. The spring rings are simulated by establishing a rotation pair between the main nodes of the RBE2 units tied at both ends, so as to realize the function of the front lock hook model 1 and the rear lock hook model 4 to lock the side panels of the cargo box.

[0068] In some alternative embodiments: See Figure 3 As shown, an embodiment of the present application provides a strength analysis method for a small truck without a front fender and cargo box. In this method, a small truck simulation model includes a body-in-white (BIW) and front and rear suspension mounting points connected to the body-in-white. During simulation testing, the maximum acceleration for each operating condition is obtained by collecting a road load spectrum from a proving ground. The front and rear suspension mounting points are then loaded according to the maximum acceleration for each operating condition, outputting stress and torque.

[0069] The front suspension mounting points include the front suspension strut upper mounting point 6 for the front McPherson suspension simulation model, the front lower arm front mounting point 7, and the front lower arm rear mounting point 8. The rear suspension mounting points include the rear leaf spring front mounting point 9, the rear suspension limiter mounting point 10, and the rear leaf spring rear mounting point 11 for the rear leaf spring suspension simulation model.

[0070] Under different simulation conditions, the front suspension strut mounting point 6, the front lower arm mounting point 7, the front lower arm mounting point 8, the rear leaf spring front mounting point 9, the rear leaf spring limiter mounting point 10 and the rear leaf spring rear mounting point 11 of the rear leaf spring suspension simulation model are simultaneously loaded with the forces and moments output by the dynamic model, and the loading method of the left and right sides of the vehicle is made consistent.

[0071] After the simulation test, the results of the static analysis using the inertia release method were analyzed. When using the inertia release function for static analysis, only one node needs to be constrained with six degrees of freedom (virtual support). For this support, the program first calculates the acceleration of each node in each direction under the action of the external force. It then converts the acceleration into an inertial force and applies it in reverse to each node, thus constructing a balanced force system (with support reaction equal to zero). The resulting displacement describes the relative motion of all nodes with respect to the support.

[0072] How it works

[0073] An embodiment of the present application provides a strength analysis method for a small truck without a front fender cargo box. The strength analysis method for a small truck without a front fender cargo box of the present application first establishes a simulation model of a small truck without a front fender cargo box, and establishes a simulation model in which the cargo box side panel 3 and the cab rear panel 2 are connected by a front locking hook model 1, and the cargo box side panel 3 and the cargo box rear panel 5 are connected by a rear locking hook model 4; then, according to different simulation working conditions, the front locking hook model 1 is adjusted to constrain the degrees of freedom of the cargo box side panel 3 and the cab rear panel 2, and the rear locking hook model 4 is adjusted to constrain the degrees of freedom of the cargo box side panel 3 and the cargo box rear panel 5; finally, for different simulation working conditions, a simulation test is carried out on the small truck simulation model established based on the constrained degrees of freedom of the front locking hook model 1 and the rear locking hook model 4 to obtain simulation results, and the structural strength of the small truck simulation model is characterized according to the simulation results.

[0074] Therefore, before conducting a body strength analysis of a small truck without a front fender cargo box, this application adjusts the front lock hook model 1 to constrain the degrees of freedom of the cargo box side panel 3 and the cab rear panel 2, and adjusts the rear lock hook model 4 to constrain the degrees of freedom of the cargo box side panel 3 and the cargo box rear panel 5, according to the body structure characteristics of the small truck without a front fender cargo box and different simulation working conditions.

[0075] Under different simulation conditions, the kinematic pair of the front hook model 1 changes with the working conditions, while the kinematic pair of the rear hook model 4 does not change with the working conditions. Therefore, this application simplifies the establishment of finite element models of the front hook model 1 and the rear hook model 4 through different simulation conditions. By utilizing the deformation trend of the entire vehicle, the connection method of the front hook model 1 and the rear hook model 4 is optimized for different working conditions to further ensure the accuracy of the vehicle strength analysis.

[0076] In the description of this application, it should be noted that the terms "upper" and "lower" and the like 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 this application and simplifying the description, and do not indicate or imply 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 this 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 an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0077] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any 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 comprising 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, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0078] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A strength analysis method for a small truck without a front fender cargo box, characterized in that: include: A simulation model of a small truck without a front fender cargo box is established, wherein the cargo box side fender (3) is connected to the cab rear fender (2) using a front lock hook model (1), and the cargo box side fender (3) is connected to the cargo box rear fender (5) using a rear lock hook model (4); According to different simulation working conditions, the degrees of freedom of the front lock hook model (1) constraining the cargo box side panel (3) and the cab rear panel (2) are adjusted, and the degrees of freedom of the rear lock hook model (4) constraining the cargo box side panel (3) and the cargo box rear panel (5) are adjusted; According to different simulation working conditions, a small truck simulation model established based on the constraint degrees of freedom of the front lock hook model (1) and the rear lock hook model (4) is simulated to obtain simulation results, and the structural strength of the small truck simulation model is characterized according to the simulation results; In the simulation working condition of vertical impact, the small truck simulation model uses the RBE2 unit to adjust the front lock hook model (1) to constrain the degrees of freedom of the cargo box side panel (3) and the cab rear panel (2), so that the kinematic pair of the cargo box side panel (3) and the cab rear panel (2) releases the degrees of freedom of Z-axis movement, Z-axis rotation and X-axis movement; The rear hook model (4) is adjusted using the RBE2 unit to constrain the degrees of freedom of the cargo box side panel (3) and the cargo box rear panel (5), so that the kinematic pairs of the cargo box side panel (3) and the cargo box rear panel (5) release the degrees of freedom of Z-axis movement and Z-axis rotation.

2. The strength analysis method for a small truck without a front fender cargo box according to claim 1, characterized in that: The small truck simulation model uses the RBE2 unit to adjust the front hook model (1) to constrain the degrees of freedom of the cargo box side panel (3) and the cab rear panel (2) under the braking simulation working condition, so that the kinematic pair of the cargo box side panel (3) and the cab rear panel (2) releases the degrees of freedom of Z-axis movement, Z-axis rotation and X-axis movement; The rear hook model (4) is adjusted using the RBE2 unit to constrain the degrees of freedom of the cargo box side panel (3) and the cargo box rear panel (5), so that the kinematic pairs of the cargo box side panel (3) and the cargo box rear panel (5) release the degrees of freedom of Z-axis movement and Z-axis rotation.

3. The strength analysis method for a small truck without a front fender cargo box according to claim 1, characterized in that: In the simulation working condition of steering, the small truck simulation model uses the RBE2 unit to adjust the front lock hook model (1) to constrain the degrees of freedom of the cargo box side panel (3) and the cab rear panel (2), so that the kinematic pair of the cargo box side panel (3) and the cab rear panel (2) releases the degrees of freedom of Z-axis movement and Z-axis rotation; The rear hook model (4) is adjusted using the RBE2 unit to constrain the degrees of freedom of the cargo box side panel (3) and the cargo box rear panel (5), so that the kinematic pairs of the cargo box side panel (3) and the cargo box rear panel (5) release the degrees of freedom of Z-axis movement and Z-axis rotation.

4. The strength analysis method for a small truck without a front fender cargo box according to claim 1, characterized in that: The method further includes judging whether the simulation result is reasonable, wherein the simulation result includes a stress threshold and a displacement threshold. If so, the simulation result is output; if not, the degree of freedom of the front lock hook model (1) constraining the cargo box side panel (3) and the cab rear panel (2) is readjusted, and the degree of freedom of the rear lock hook model (4) constraining the cargo box side panel (3) and the cargo box rear panel (5) is readjusted, and the simulation is performed again.

5. The strength analysis method for a small truck without a front fender cargo box according to claim 1, characterized in that: The front lock hook model (1) includes a rear panel bolt connection bracket (12) bolted to the cab rear panel (2), and a side panel connection bracket (13) bolted to the cargo box side panel (3); The overlapping bend of the rear panel bolt connection bracket (12) and the overlapping notch of the side panel baffle connection bracket (13) are connected as a kinematic pair through the RBE2 unit.

6. The strength analysis method for a small truck without a front fender cargo box according to claim 1, characterized in that: The rear lock hook model (4) includes a side panel welding bracket (14) welded to the cargo box side panel (3), and a rear panel connecting bracket (15) bolted to the cargo box rear panel (5); The overlapping bend of the side panel welding bracket (14) and the overlapping notch of the rear panel connecting bracket (15) are used as a kinematic pair through the RBE2 unit.

7. The strength analysis method for a small truck without a front fender cargo box according to claim 1, characterized in that: The small truck simulation model includes a body-in-white, and front and rear suspension mounting points connected to the body-in-white; During the simulation test, the maximum acceleration of each working condition is obtained by collecting the road load spectrum of the test site. The front and rear suspension mounting points are loaded according to the maximum acceleration of each working condition to output stress and torque.

8. The strength analysis method for a small truck without a front fender cargo box according to claim 7, characterized in that: The front suspension mounting point includes a front suspension sliding column upper mounting point (6) for mounting a front McPherson suspension simulation model, a front lower suspension arm front mounting point (7) and a front lower suspension arm rear mounting point (8), and the rear suspension mounting point includes a rear leaf spring front mounting point (9), a rear suspension limiter mounting point (10) and a rear leaf spring rear mounting point (11) of a rear leaf spring suspension simulation model.

9. The strength analysis method for a small truck without a front fender cargo box according to claim 1, characterized in that: After the simulation test, the inertia release method is used to statically analyze the simulation results.

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