Body-in-white bending rigidity simulation load applying device and load applying method thereof

Abstract

The invention discloses a body-in-white bending rigidity simulation load applying device and a load applying method thereof. The body-in-white bending rigidity simulation load applying device comprises a simulation rod piece used for applying a load and a simulation plate piece which is fixedly connected to the lower portion of the simulation rod piece through a one-dimensional connecting beam unit and used for transmitting the load to a load applying position of a body-in-white bending rigidity simulation test. The left side and the right side of the simulation rod piece are symmetrically connected with at least one simulation plate piece respectively. By means of the designed simulation loading device, the bending rigidity of the body in white can be simply, accurately and rapidly obtained, the bending rigidity performance of the body in white can be accurately evaluated in the early stage of project development, the development efficiency of the body in white is improved, repeated modification work in the later physical stage caused by inaccurate performance evaluation in the early stage is avoided, and the development efficiency of the body in white is improved. And the development cost and time are saved.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle testing, and in particular to a body-in-white bending stiffness simulation load applying device and a load applying method thereof. Background Art

[0002] The stiffness of the body in white is an important performance indicator of the body in white, reflecting its ability to resist deformation. The stiffness of the body in white is related to performance such as NVH, fatigue, and handling stability. Therefore, during the design stage, it is necessary to maximize the stiffness of the body in white while controlling the weight of the body in white.

[0003] However, in the design stage, since the body-in-white is not produced, it is impossible to directly perform bending tests on the body-in-white, and simulation methods are needed to evaluate the body stiffness. Therefore, the results of the simulation method used to evaluate the body stiffness should be consistent with the evaluation results of the actual bending test in order to provide better guidance for the design.

[0004] At present, the load loading method for BIW bending stiffness simulation is: loading the simulated load on the door sill beam or the seat mounting point or the seat H point. When performing actual bending test on BIW, it is usually adopted to pile sandbags at the loading point of BIW or to load the loading point of BIW through a loading device. The bending simulation test of BIW is to load a part or point of BIW with concentrated force, while the actual bending test of BIW is usually to load a load part with a larger area. At the same time, there are differences between the simulated loading and actual loading positions of BIW. Therefore, there is a large error between the bending simulation and actual test results of BIW, which affects the development work in the design stage. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the above-mentioned background technology and provide a body-in-white bending stiffness simulation load application device and a load application method thereof, which can ensure the consistency between the simulation test and the actual test results and effectively improve the simulation efficiency and accuracy.

[0006] To achieve this purpose, the body-in-white bending stiffness simulation load application device designed in the present invention includes a simulation rod for applying a load and a simulation plate fixedly connected to the bottom of the simulation rod through a one-dimensional connecting beam unit and used to transfer the load to the load application point of the body-in-white bending stiffness simulation test; at least one simulation plate is symmetrically connected to the left and right sides of the simulation rod.

[0007] Furthermore, the simulation rod member includes a plurality of one-dimensional beam units arranged in the same direction and fixedly connected end to end to form an integrated structure.

[0008] Furthermore, the simulation plate includes at least two shell units symmetrically connected below the simulation rod.

[0009] Furthermore, the shell unit is composed of a plurality of grid units.

[0010] Furthermore, the shell unit is a regular polygon structure with multiple vertices, and the vertices of the same shell unit are fixedly connected to a node of the one-dimensional beam unit on one side of the simulation rod through a one-dimensional connecting beam unit.

[0011] A load application method based on the above-mentioned body-in-white bending stiffness simulation load application device includes: importing the body-in-white bending stiffness simulation load application device into the body-in-white mesh model, setting the material properties of the body-in-white bending stiffness simulation load application device and the bending load loading position of the body-in-white bending stiffness simulation load application device on the body-in-white, applying a load to the body-in-white bending stiffness simulation load application device, and judging whether the body-in-white bending stiffness meets the requirements.

[0012] Furthermore, the method for setting the bending load loading position of the body-in-white bending stiffness simulation load applying device on the body-in-white is: two of the body-in-white bending stiffness simulation load applying devices are respectively set above the front and rear row seat sheet metals of the body-in-white, the simulation rods are arranged along the width direction of the body, the simulation panel is located directly above the seat sheet metal, and the distance L between the simulation panel and the seat sheet metal is set.

[0013] Furthermore, the distance L between the simulation panel and the seat sheet metal is 0.5t-t, where t is the thickness of the seat sheet metal.

[0014] Furthermore, applying the load to the BIW bending stiffness simulation load applying device includes: applying the load symmetrically along the height direction of the BIW at the two end nodes of the simulation rod.

[0015] Furthermore, the method for determining whether the bending stiffness of the body-in-white meets the requirements is: calculating the bending stiffness of the body-in-white in a simulated bending test, comparing the bending stiffness of the body-in-white in a simulated bending test with a set value; if the bending stiffness of the body-in-white in a simulated bending test is not less than the set value, the bending stiffness of the body-in-white meets the requirements; otherwise, the bending stiffness of the body-in-white does not meet the requirements.

[0016] Furthermore, the calculation formula for the bending stiffness of the simulated bending test of the body in white is: K=F / d, wherein K is the bending stiffness of the simulated bending test of the body in white, F is the load applied to the body in white bending stiffness simulation load application device, and d is the maximum deformation of the body in white sill beam in the body height direction.

[0017] The beneficial effects of the present invention are as follows: the present invention designs a load application device for simulation for the bending stiffness test of the body-in-white. By combining the simulation rod and the simulation plate, the device can ensure the size and direction of the load during loading, and has good calculation accuracy. The simulation loading device is consistent with the loading device structure used for the actual bending test of the body-in-white. By applying the -Z direction load at both ends of the simulation rod, the point-based simulation load is formed into a surface-based simulation load through the simulation plate, which corresponds to the surface-based loading method in the actual bending test of the body-in-white (such as stacking sandbags above the seat sheet metal, etc.). The load application method based on the simulation loading device maintains good consistency with the actual bending test, solving the problem that the simulation and actual measurement results are inconsistent and trouble the initial design; at the same time, the simulation loading device model designed by the present invention can be directly reused after the establishment is completed, which improves the simulation efficiency. In summary, the simulation loading device designed by the present invention can be used to obtain the bending stiffness of the body-in-white simply, accurately and quickly, and the bending stiffness performance of the body-in-white can be accurately evaluated in the early stage of project development, which improves the development efficiency of the body-in-white, avoids the repeated modification work in the later physical stage due to inaccurate early performance evaluation, and saves development costs and time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional diagram of the body-in-white bending stiffness simulation load application device in the present invention;

[0019] Figure 2 It is a front view of the load loading structure of the load applying device for simulating the bending stiffness of the body in white in the present invention;

[0020] Among them, 1 is a simulated rod (1.1 is a one-dimensional beam element), 2 is a simulated plate (2.1 is a shell element), and 3 is a one-dimensional connecting beam element. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. In the description of the present invention, it should be understood that the orientations or positional relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention 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 limiting the present invention.

[0022] like Figure 1—2, the body-in-white bending stiffness simulation load application device designed by the present invention comprises a simulation rod 1 for applying load and a simulation plate 2 fixedly connected to the bottom of the simulation rod 1 through a one-dimensional connecting beam unit 3 and used for transferring the load to the load application location of the body-in-white bending stiffness simulation test; at least one simulation plate 2 is symmetrically connected to the left and right sides of the simulation rod 1.

[0023] Embodiment 1 of the simulation rod 1:

[0024] The simulation rod 1 comprises a plurality of one-dimensional beam units 1.1 arranged in the same direction and fixedly connected end to end to form an integrated structure.

[0025] Embodiment 1 of the simulation board 2:

[0026] The simulation plate 2 comprises at least two shell elements 2.1 symmetrically connected to the bottom of the simulation rod 1, and the shell element 2.1 is composed of a plurality of grid elements.

[0027] Embodiment 2 of the simulation board 2:

[0028] Based on the above-mentioned embodiment 1 of the simulation plate 2, the shell element 2.1 is optimized and designed as follows:

[0029] The shell element 2.1 is a regular polygonal structure with multiple vertices. The vertices of the same shell element 2.1 are all fixedly connected to a node of the one-dimensional beam element 2.1 on one side of the simulation rod 2 through a one-dimensional connecting beam element 3.

[0030] Embodiment 1 of the load application method based on the above-mentioned body-in-white bending stiffness simulation load application device:

[0031] Import the BIW bending stiffness simulation load application device into the BIW mesh model, set the material properties of the BIW bending stiffness simulation load application device and the bending load loading position of the BIW bending stiffness simulation load application device on the BIW, apply load to the BIW bending stiffness simulation load application device, and judge whether the BIW bending stiffness meets the requirements.

[0032] Embodiment 1 of the method for setting the bending load loading position of the body-in-white bending stiffness simulation load applying device on the body-in-white:

[0033] Two BIW bending stiffness simulation load application devices are respectively arranged above the front and rear row seat sheet metals of the BIW, the simulation rod 1 is arranged along the width direction of the vehicle body, the simulation panel 2 is located directly above the seat sheet metal, and the distance L between the simulation panel 2 and the seat sheet metal is set, L is 0.5t, and t is the thickness of the seat sheet metal.

[0034] Embodiment 1 of applying load to the body-in-white bending stiffness simulation load applying device:

[0035] Loads are applied symmetrically at both end nodes of the simulation rod 2 along the height direction of the body-in-white.

[0036] Embodiment 1 of the method for judging whether the bending stiffness of the body-in-white meets the requirements:

[0037] The bending stiffness of the simulated bending test of the body in white is calculated, and the bending stiffness of the simulated bending test of the body in white is compared with the set value. If the bending stiffness of the simulated bending test of the body in white is not less than the set value, the bending stiffness of the body in white meets the requirements, otherwise the bending stiffness of the body in white does not meet the requirements. The calculation formula of the bending stiffness of the simulated bending test of the body in white is: K=F / d, wherein K is the bending stiffness of the simulated bending test of the body in white, F is the load applied by the load application device for the bending stiffness simulation of the body in white, and d is the maximum deformation of the sill beam of the body in white in the height direction of the body.

[0038] A specific embodiment of the body-in-white bending stiffness simulation load application device is described below.

[0039] like Figure 1 As shown in FIG. 2 , the present invention is a load application device for simulating bending stiffness of a body-in-white for computer simulation. A finite element model of the device is established in a computer, and in combination with a finite element model of the body, a virtual simulation of the bending stiffness of the body-in-white can be performed. After the device is established, it can be stored in a computer medium, and the model can be directly imported for use in the development of different vehicle models.

[0040] The vehicle coordinate system is defined as follows: the X direction is the longitudinal direction of the vehicle, from the front to the rear; the Y direction is the lateral direction of the vehicle, from left to right; and the Z direction is the height direction of the vehicle, from bottom to top.

[0041] The structure of the load application device for BIW bending stiffness simulation is as follows: Figure 1 As shown in FIG. 2 , the device is a rigid loading beam structure, which is composed of 4 one-dimensional beam units 1.1, 8 one-dimensional connecting beam units 3 and two shell units 2.1 (which can be divided into several grid units), and contains 13 main nodes and shell units. The beam unit is used to simulate the rod in the real object, and the shell unit 2.1 is used to simulate the plate in the real object. The shell unit 2.1 is square, and the one-dimensional beam unit 1.1 and the one-dimensional connecting beam unit 3 have the same structure, material and size. The device is bilaterally symmetrical (symmetrical about the plane of the whole vehicle coordinate Y=0), and the middle node of the simulation rod 1 is a symmetrical point, which is located on the plane of the whole vehicle coordinate Y=0. Constraining the degree of freedom of this point can limit the translational freedom of the simulation loading device in the X and Y directions and the rotational freedom in the X, Y and Z directions, ensuring that the simulation loading device has only displacement in the Z direction, and no movement and rotation in other directions. The load applied by the simulation loading device on the vehicle body is bilaterally symmetrical, and the length and size of the device can be adjusted according to the size of the vehicle body.

[0042] After determining the structure and size of the simulation loading device, set the material properties of the simulation loading device: the simulation loading device designed by the present invention has the same structure as the loading device used in the actual bending test of the body-in-white. If the bending stiffness test device of the body-in-white is unified, the specific parameters of the simulation loading model can be assigned according to the actual plate thickness and cross-section parameters of the crossbeam of the body-in-white bending test device. If the body-in-white bending test device is not unified, that is, there are multiple bending test mechanisms and multiple test loading devices, the specific parameters of the simulation model are assigned with reference to the body-in-white bending test device with the largest stiffness.

[0043] After determining the structure, size and material properties of the simulation loading device, the use of the simulation loading device is as follows: the device is imported into the body-in-white mesh model, and then two simulation loading devices are imported. The two simulation loading devices are placed on the front and rear seat sheet metals respectively. The distance between the bottom surface of the shell unit 2.1 of the simulation loading device and the body-in-white sheet metal is 0.5t (t is the thickness of the sheet metal under the shell unit 2.1), and the contact relationship between the shell unit 2.1 and the body sheet metal is established. The distance between the bottom surface of the shell unit 2.1 of the simulation loading device and the body-in-white sheet metal is set to 0.5t. When a -Z load is applied to the simulation loading device, the shell unit 2.1 will move downward and contact the body, avoiding the influence of the shell unit 2.1 itself on the body-in-white bending test, and ensuring that the test structure of the body-in-white bending simulation test is consistent with the test results of the actual bending test.

[0044] Calculation of the bending stiffness of the body in white. Figure 2 A -Z load is applied to the node shown, and the load is transferred to the shell unit 2.1 through the loading device, and then transferred to the body through the contact relationship between the shell unit 2.1 and the body, causing the body to deform. The maximum deformation of the sill beam in the Z direction is measured by the post-processing software. The bending stiffness of the body-in-white is calculated by the following formula: K=F / d. K-bending stiffness, F-load size, d-maximum deformation of the sill in the Z direction. The bending stiffness of the simulated bending test of the body-in-white is compared with the set value. If the bending stiffness of the simulated bending test of the body-in-white is not less than the set value, the bending stiffness of the body-in-white meets the requirements, otherwise the bending stiffness of the body-in-white does not meet the requirements. The size of the simulated load F in the present invention can be set according to the load of the actual bending test of the body-in-white to ensure that the load loading value of the simulated panel 2 for the body seat sheet metal is the same as the load value received by the actual bending test of the body-in-white.

[0045] The present invention designs a load application device for simulation for the bending stiffness test of the body in white. Through the combination of the simulation rod 1 and the simulation plate 2, the device can ensure the size and direction of the load during loading, and has good calculation accuracy. The simulation loading device is consistent with the loading device structure used for the actual bending test of the body in white. By applying the -Z direction load at both ends of the simulation rod 1, the point-based simulation load is formed into a surface-based simulation load through the simulation plate 2, which corresponds to the surface-based loading method in the actual bending test of the body in white (such as stacking sandbags above the seat sheet metal, etc.). The load application method based on the simulation loading device maintains good consistency with the actual bending test, solving the problem that the simulation and actual measurement results are inconsistent and trouble the initial design; at the same time, the simulation loading device model designed by the present invention can be directly reused after the establishment is completed, which improves the simulation efficiency. In summary, the simulation loading device designed by the present invention can be used to obtain the bending stiffness of the body in white simply, accurately and quickly, and the bending stiffness performance of the body in white can be accurately evaluated in the early stage of project development, which improves the efficiency of the body in white development, avoids repeated modifications in the later physical stage due to inaccurate early performance evaluation, and saves development costs and time.

[0046] It should be noted here that the description of the above technical solutions is exemplary, and this specification can be embodied in different forms and should not be interpreted as being limited to the technical solutions set forth herein. On the contrary, providing these descriptions will make the disclosure of the present invention thorough and complete, and will fully convey the scope disclosed in this specification to those skilled in the art. In addition, the technical solution of the present invention is limited only by the scope of the claims. In the case of using "including", "having" and "comprising" described in this specification, there may also be another part or other parts, and the terms used may generally be singular but may also represent plural forms.

[0047] Finally, it should be pointed out that the above embodiments are only representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments, and there are many variations. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention should be considered to belong to the protection scope of the present invention.

Claims

1. A body-in-white bending stiffness simulation load application device, characterized in that: It comprises a simulation rod (1) for applying a load and a simulation plate (2) fixedly connected to the bottom of the simulation rod (1) via a one-dimensional connecting beam unit (3) and used to transfer the load to the load application location of the body-in-white bending stiffness simulation test; at least one simulation plate (2) is symmetrically connected to the left and right sides of the simulation rod (1) respectively.

2. The body-in-white bending stiffness simulation load application device according to claim 1, characterized in that: The simulation rod (1) comprises a plurality of one-dimensional beam units (1.1) arranged in the same direction and fixedly connected end to end to form an integrated structure.

3. The body-in-white bending stiffness simulation load application device according to claim 2, characterized in that: The simulation plate (2) comprises at least two shell units (2.1) symmetrically connected below the simulation rod (1).

4. The body-in-white bending stiffness simulation load application device according to claim 3, characterized in that: The shell element (2.1) is composed of a plurality of mesh elements.

5. The body-in-white bending stiffness simulation load application device according to claim 3, characterized in that: The shell unit (2.1) is a regular polygonal structure having multiple vertices, and the vertices of the same shell unit (2.1) are all fixedly connected to a node of the one-dimensional beam unit (2.1) on one side of the simulation rod (2) through a one-dimensional connecting beam unit (3).

6. A load application method based on the body-in-white bending stiffness simulation load application device according to any one of claims 1 to 5, characterized in that: The method includes importing the body-in-white bending stiffness simulation load application device into the body-in-white mesh model, setting the material properties of the body-in-white bending stiffness simulation load application device and the bending load loading position of the body-in-white bending stiffness simulation load application device on the body-in-white, applying a load to the body-in-white bending stiffness simulation load application device, and judging whether the body-in-white bending stiffness meets the requirements.

7. The load applying method of the body-in-white bending stiffness simulation load applying device according to claim 6, characterized in that: The method for setting the bending load loading position of the body-in-white bending stiffness simulation load application device on the body-in-white is as follows: two of the body-in-white bending stiffness simulation load application devices are respectively set above the front and rear row seat sheet metals of the body-in-white, the simulation rod (1) is arranged along the width direction of the body, the simulation panel (2) is located directly above the seat sheet metal, and a distance L is set between the simulation panel (2) and the seat sheet metal.

8. The load applying method of the body-in-white bending stiffness simulation load applying device according to claim 7, characterized in that: The distance L between the simulation plate (2) and the seat sheet metal is 0.5t-t, where t is the thickness of the seat sheet metal.

9. The load applying method of the body-in-white bending stiffness simulation load applying device according to claim 7, characterized in that: Applying a load to the body-in-white bending stiffness simulation load applying device comprises: applying a load symmetrically along the height direction of the body-in-white at the two end nodes of the simulation rod (2).

10. The load applying method of the body-in-white bending stiffness simulation load applying device according to claim 9, characterized in that: The method for judging whether the bending stiffness of the body-in-white meets the requirements is: calculating the bending stiffness of the body-in-white in a simulated bending test, comparing the bending stiffness of the body-in-white in a simulated bending test with a set value, if the bending stiffness of the body-in-white in a simulated bending test is not less than the set value, the bending stiffness of the body-in-white meets the requirements, otherwise the bending stiffness of the body-in-white does not meet the requirements; The calculation formula for the bending stiffness of the simulated bending test of the body in white is: K=F / d, wherein K is the bending stiffness of the simulated bending test of the body in white, F is the load applied to the body in white bending stiffness simulation load application device, and d is the maximum deformation of the body in white sill beam in the body height direction.

Images