Arrangement method and simulation analysis method of weakening line of vehicle door protection plate and vehicle door protection plate

Abstract

The invention discloses a vehicle door protection plate weakening line arrangement method, a simulation analysis method and a vehicle door protection plate, and the arrangement method comprises the steps: arranging a weakening line in a Z direction under a whole vehicle coordinate system, and enabling the weakening line to penetrate through the vehicle door protection plate; based on the side column collision working condition of the C-NCAP regulation, a driving position dummy is arranged; the position of the weakening line in the X direction of the vehicle door protection plate is determined according to the relative position of the head mass center of the driving position dummy and the vehicle door protection plate; when a side column of a vehicle is collided, the front door protection plate can be bent at the weakening line to prevent the buckle from falling off, so that the front door protection plate is tightly attached to the vehicle door metal plate, the distance between the front door protection plate and a passenger is increased, the chest space and the abdomen space are increased, the injury to the passenger is reduced, and the collision safety performance of the vehicle is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle safety protection, and in particular to a method for arranging a door guard plate weakening line, a simulation analysis method and a door guard plate. Background Art

[0002] With the rapid development of the automobile industry and the continuous updating and iteration of domestic and international new car assessment programs (C-NCAP and Euro NCAP), the requirements for automobile safety performance are becoming higher and higher. Improving automobile safety performance is becoming increasingly important in the product development process.

[0003] According to research, in actual traffic accidents in China, 38% of the cases of death caused by single-vehicle side-slipping and hitting large trees, electric poles, sign posts and other objects were caused by the occupants' heads hitting trees or columnar objects. The so-called columnar objects usually refer to cylindrical rigid objects such as signal traffic sign poles, light poles, telephone poles, electric poles, large trees, fire hydrants, etc. When a car side-slips, it often collides with these cylindrical rigid objects, causing the side of the car to directly hit the obstacle. The stiffness of these obstacles is often large, and the collision contact surface is small, resulting in the amount of intrusion of these obstacles into the local side of the vehicle than the amount of intrusion in the side collision of two vehicles that usually occurs at a road intersection, resulting in a smaller survival space for the occupants, which will cause very serious injuries to the occupants in the car.

[0004] Since the side pole collision is more complex, it not only includes the lateral translation of the vehicle, but also the rotation around the collision interface and its own center of gravity. The rotation of the vehicle body around its own center of gravity will cause the collision path to deflect. Therefore, the degree of injury to the occupants in a side pole collision is higher than that of a general side collision, causing a great risk of injury to the occupants' heads and chests, and the local assessment of the vehicle body is also stricter than that of a general side collision. Therefore, C-NCAP and Euro NCAP regulations list side pole collisions as regulatory assessment items.

[0005] Up to now, in the development of most vehicles, the front door guards are all one-piece structures. In the side pillar collision test conditions, the front door sheet metal will undergo significant deformation. Since the door guards are one-piece structures, the door guards will not deform with the sheet metal, which will cause the front door guards near the B-pillar to snap off, making the distance between the door guards and the front passengers smaller, increasing the compression of the occupants' chests and abdomens, etc. At the same time, there is a risk of puncturing the side airbags, resulting in direct hard contact between the occupants and the door guards, causing serious injuries to the dummies. The above problems need to be solved urgently. Summary of the invention

[0006] The object of the present invention is to provide a door guard plate weakening line arrangement method, a simulation analysis method and a door guard plate to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solution: a method for arranging a weakening line of a door guard plate, comprising:

[0008] In the Z direction of the vehicle coordinate system, a weakening line is arranged so as to penetrate the door guard plate;

[0009] Based on the C-NCAP regulations side column collision conditions, a dummy is placed in the driving seat;

[0010] The position of the weakening line in the X direction of the door guard plate is determined according to the relative position of the center of mass of the head of the driver's seat dummy and the door guard plate.

[0011] Furthermore, when the vehicle collides with a side column, the front door guard plate is bent at the position of the weakening line by setting the weakening line, so that the front door guard plate fits tightly with the door sheet metal.

[0012] Furthermore, the position of the weakening line in the X direction of the door guard plate is determined according to the relative position of the head center of mass of the driver's seat dummy and the door guard plate, and also includes a calculation formula for the position of the weakening line in the X direction of the door guard plate:

[0013] d = D × tan (90° - θ) - formula (1);

[0014] Where: According to the C-NCAP regulations side pole collision condition, the angle between the calibrated vehicle collision velocity vector line and the vehicle's X-axis centerline is θ = 75°; D is the Y-axis distance between the center of mass of the driver dummy's head and the front door guard plate in the side pole collision condition; d is the X-axis distance between the Y-axis projection of the center of mass of the head on the door guard plate and the weakening line.

[0015] On the other hand, a simulation analysis method for a door guard weakening line is provided, comprising:

[0016] Establishing a three-dimensional data model of the whole vehicle and dividing the finite element mesh, wherein the three-dimensional data model of the whole vehicle includes a three-dimensional data model of the front door guard plate with a weakening line;

[0017] Assigning properties to materials;

[0018] Set boundary conditions;

[0019] Conduct finite element simulation analysis;

[0020] The compression of the chest and abdominal ribs of the dummy is obtained based on the simulation analysis results.

[0021] Furthermore, the 3D data model of the whole vehicle also includes the body in white, instrument panel, sub-instrument panel, front door guard plate, driver's seat, carpet, seat belt and driver's side WorldSID 50 th Dummy model.

[0022] Furthermore, after the 3D data of the front door guard plate with the weakening line is modeled and the finite element mesh is divided, the following steps are also included:

[0023] The front door guard plate with a weakened line is flexibly connected to the front door sheet metal according to the actual installation method.

[0024] Furthermore, assigning material properties also includes:

[0025] Set the material and thickness related parameters in the primer software according to the material properties.

[0026] Furthermore, setting boundary conditions also includes:

[0027] The acceleration waveform of the vehicle side column collision test is applied to the body in white, and the gravity field, time step, time step scaling factor, and calculation termination time are set for the entire model.

[0028] Furthermore, the rib compression of the chest and abdomen of the dummy is obtained according to the simulation analysis results, which also includes:

[0029] According to the simulation analysis results of the door guard plate with a weakening curve set, when the front door guard plate is closely attached to the door sheet metal near the B-pillar, a first curve of the compression of the abdominal ribs at the ribs of the simulated dummy and a second curve of the compression of the dummy chest at the dummy chest are extracted;

[0030] According to the simulation analysis results of the door guard plate without a weakening curve, a third curve of the compression of the abdominal ribs at the ribs of the simulation dummy and a fourth curve of the compression of the dummy chest at the dummy chest are extracted;

[0031] By comparing the first curve and the third curve, and the second curve and the fourth curve, it is determined that the front door guard plate with the weakened line has the effect of reducing the compression amount of the abdominal ribs.

[0032] On the other hand, a vehicle door guard plate having a weakening line is provided, which is arranged using the method for arranging a vehicle door guard plate weakening line as described in any one of claims 1 to 3.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows: when the vehicle collides with a side pillar, the front door guard plate will bend at the weakening line to prevent the buckle from falling off, and then fit tightly with the door sheet metal, thereby increasing the distance between the door guard plate and the occupant, increasing the chest and abdominal space, thereby reducing occupant injuries and greatly improving the safety performance of the vehicle's pillar collision. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a flow chart of a method for arranging a weakening line of a door guard plate in an embodiment of the present invention;

[0035] Figure 2Schematic diagram of a front door guard plate with a weakening line in an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of a side column collision test in an embodiment of the present invention;

[0037] Figure 4 Schematic diagram of a simulation method for a weakening line of a door guard plate in an embodiment of the present invention;

[0038] Figure 5 Schematic diagram of chest rib compression curve comparison in an embodiment of the present invention;

[0039] Figure 6 Schematic diagram of the comparison of abdominal rib compression curves in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", 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, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" 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. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] Please refer to the attached drawings of the specification, the present invention provides a technical solution: Figure 1 As shown, a method for arranging a weakening line of a door guard plate includes the following steps:

[0044] S102, such as Figure 2As shown, in the Z direction of the vehicle coordinate system, a weakening line is arranged so as to penetrate the door guard plate;

[0045] Among them, in the Z direction, the weakening line runs through the entire height of the door guard plate;

[0046] S104. Arrange a dummy in the driver's seat based on the C-NCAP regulations side column collision condition;

[0047] S106. Determine the position of the weakening line in the X direction of the door guard plate according to the relative position of the center of mass of the head of the driver's seat dummy and the door guard plate.

[0048] Specifically, when the vehicle collides with a side pole, the front door guard plate is bent at the position of the weakening line by setting the weakening line, so that the front door guard plate is closely fitted to the door sheet metal.

[0049] Among them, when the vehicle collides with a side pole under the side pole collision conditions based on the C-NCAP regulations, the front door guard panel with a weakening line will bend at the weakening line position to prevent the buckle from falling off, and then fit tightly with the door sheet metal, increasing the distance between the door guard panel and the occupant.

[0050] Specifically, Figure 3 As shown, the position of the weakening line in the X direction of the door guard plate is determined according to the relative position of the head center of mass of the driver's seat dummy and the door guard plate, and also includes a calculation formula for the position of the weakening line in the X direction of the door guard plate:

[0051] d = D × tan (90° - θ) - formula (1);

[0052] Where: According to the C-NCAP regulations side pole collision condition, the angle between the calibrated vehicle collision velocity vector line and the vehicle's X-axis centerline is θ = 75°; D is the Y-axis distance between the center of mass of the driver dummy's head and the front door guard plate in the side pole collision condition; d is the X-axis distance between the Y-axis projection of the center of mass of the head on the door guard plate and the weakening line.

[0053] Among them, the layout position of the weakening line is determined by formula 1, and the layout position in the X direction is strongly related to the impact position of the rigid column in the side column collision condition, such as Figure 3 As shown, it is a schematic diagram of the side column collision condition, wherein at the impact position, the angle between the vertical plane (parallel to the vehicle collision velocity vector line) and the longitudinal center line of the vehicle is 75°, the allowable error in the test is ±3°, the diameter of the preferred rigid column is 254mm, and the speed in the collision velocity vector direction of the collision test is set to V=32km / h, thereby the X-direction arrangement position of the weakening line can be obtained.

[0054] On the other hand, Figure 4As shown, in order to verify the correctness and rationality of the present invention, a system-level simulation analysis is performed using a front door guard plate structure with a weakening line, and compared with the calculation results of a front door guard plate without a weakening line, a simulation analysis method for a door guard plate weakening line is provided, including the following steps:

[0055] S202, establishing a three-dimensional data model of the whole vehicle and dividing the finite element mesh, wherein the three-dimensional data model of the whole vehicle includes a three-dimensional data model of a front door guard plate with a weakening line;

[0056] Specifically, the 3D data model of the whole vehicle also includes the body in white, instrument panel, auxiliary instrument panel, front door guard plate, driver's seat, carpet, seat belt and driver's side WorldSID 50 th Dummy model.

[0057] Among them, simulation is used for pre-processing, and CATIA software is used to carry out 3D data modeling of the front door guard plate structure with weakening lines, and divide the finite element mesh.

[0058] Specifically, the front door guard plate with the weakening line is flexibly connected to the front door sheet metal according to the actual installation method.

[0059] Among them, all components in the model are stored separately through sub-files, and each sub-file is called through the keyword *INCLUDE in the main file.

[0060] S204, assigning material properties;

[0061] Specifically, assigning material properties also includes:

[0062] Set the material and thickness related parameters in the primer software according to the material properties.

[0063] S206, setting boundary conditions;

[0064] Specifically, the acceleration waveform of the whole vehicle side pole collision test is applied to the white body, and the gravity field, time step, time step scaling factor, and calculation termination time are set for the entire model.

[0065] The material and thickness of each component are assigned according to the vehicle BOM. Finally, the acceleration waveform of the vehicle side column collision test is applied to the body-in-white through the LS-DYNA keyword *BOUNDARY_PRESCRIBED_MOTION. The LS-DYNA971.R9.3 MPP and above solvers are used for solving and post-processing. At the same time, the gravity field is set for the entire model, the time step TIMESTEP is set to -4e-7s, the time step scaling factor is set to 0.9, and the calculation termination time is set to 0.2s.

[0066] S208, performing finite element simulation analysis;

[0067] S210. Obtain the compression amount of the chest and abdominal ribs of the dummy according to the simulation analysis results.

[0068] Specifically, Figure 5 and 6 As shown, the compression of the chest and abdominal ribs of the dummy is obtained according to the simulation analysis results, and also includes:

[0069] According to the simulation analysis results of the door guard plate with a weakening line set, when the front door guard plate is closely attached to the door sheet metal near the B-pillar, a first curve of the compression of the abdominal ribs at the ribs of the simulation dummy and a second curve of the compression of the dummy chest at the chest of the dummy are extracted;

[0070] According to the simulation analysis results of the door guard plate without a weakening line, a third curve of the compression of the abdominal ribs at the ribs of the simulation dummy and a fourth curve of the compression of the dummy chest at the dummy chest are extracted;

[0071] By comparing the first curve and the third curve, and the second curve and the fourth curve, it is determined that the front door guard plate with the weakened line has the effect of reducing the compression amount of the abdominal ribs.

[0072] Among them, according to calculation and analysis, observe whether the front door guard plate close to the B-pillar is tightly attached to the door sheet metal during the column collision; according to the calculation data, read the compression of the chest and abdominal ribs of the dummy and compare it with the original calculation results to determine whether the structure effectively reduces the dummy's injury; Figure 5 and Figure 6 They are respectively the chest and abdominal rib compression curves of the dummy after collision. Figure 5 As shown, the red curve is the simulation analysis result of the door guard plate with a weakening line, that is, the first curve, and the black curve is the simulation analysis result of the door guard plate without a weakening line, that is, the third curve. It can be seen that the use of a front door guard plate with a weakening line can effectively reduce the compression of the dummy's chest ribs; similarly, Figure 5 As shown, the red curve is the simulation analysis result of the door guard plate with a weakening line, that is, the second curve, and the black curve is the simulation analysis result of the door guard plate without a weakening line, that is, the fourth curve. It can be seen that the use of a front door guard plate structure with a weakening line can also play an effect of reducing the compression of the abdominal ribs;

[0073] If the simulation results prove that the front door guard plate structure with weakening lines can effectively reduce the compression of the dummy's chest and abdomen, a real vehicle verification test can be carried out.

[0074] On the other hand, a vehicle door guard plate having a weakening line is provided, which is arranged using any of the above-mentioned methods for arranging a vehicle door guard plate weakening line.

[0075] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for arranging a weakening line of a door guard plate, characterized in that: include: In the Z direction of the vehicle coordinate system, a weakening line is arranged so as to penetrate the door guard plate; Based on the C-NCAP regulations side column collision conditions, a dummy is placed in the driving seat; The position of the weakening line in the X direction of the door guard plate is determined according to the relative position of the center of mass of the head of the driver's seat dummy and the door guard plate.

2. The method for arranging a weakening line of a door guard plate according to claim 1, characterized in that: When the vehicle collides with a side pole, the front door guard plate is bent at the weakening line position through the setting of the weakening line, so that the front door guard plate fits tightly with the door sheet metal.

3. The method for arranging a weakening line of a door guard plate according to claim 1, characterized in that: The position of the weakening line in the X direction of the door guard plate is determined according to the relative position of the head center of mass of the driver's seat dummy and the door guard plate, and also includes the calculation formula of the position of the weakening line in the X direction of the door guard plate: d = D × tan (90° - θ) - formula (1); Where: According to the C-NCAP regulations side pole collision condition, the angle between the calibrated vehicle collision velocity vector line and the vehicle's X-axis centerline is θ = 75°; D is the Y-axis distance between the center of mass of the driver dummy's head and the front door guard plate in the side pole collision condition; d is the X-axis distance between the Y-axis projection of the center of mass of the head on the door guard plate and the weakening line.

4. A simulation analysis method for a door panel weakening line, characterized in that: include: Establishing a three-dimensional data model of the whole vehicle and dividing the finite element mesh, wherein the three-dimensional data model of the whole vehicle includes a three-dimensional data model of the front door guard plate with a weakening line; Assigning properties to materials; Set boundary conditions; Conduct finite element simulation analysis; The compression of the chest and abdominal ribs of the dummy is obtained based on the simulation analysis results.

5. The simulation analysis method of the door panel weakening line according to claim 4, characterized in that: The 3D data model of the whole vehicle also includes the body in white, instrument panel, sub-instrument panel, front door guard plate, driver's seat, carpet, seat belt and driver's side WorldSID 50 th Dummy model.

6. The simulation analysis method of the door panel weakening line according to claim 4, characterized in that: After modeling the 3D data of the front door guard with a weakening line and dividing the finite element mesh, the following is also included: The front door guard plate with a weakened line is flexibly connected to the front door sheet metal according to the actual installation method.

7. The simulation analysis method of the door panel weakening line according to claim 4, characterized in that: Assigning material properties also includes: Set the material and thickness related parameters in the primer software according to the material properties.

8. The simulation analysis method of the door panel weakening line according to claim 4, characterized in that: Setting boundary conditions also includes: The acceleration waveform of the vehicle side column collision test is applied to the body in white, and the gravity field, time step, time step scaling factor, and calculation termination time are set for the entire model.

9. The simulation analysis method of the door panel weakening line according to claim 4, characterized in that: The rib compression of the dummy's chest and abdomen is obtained based on the simulation analysis results, including: According to the simulation analysis results of the door guard plate with a weakening curve set, when the front door guard plate is closely attached to the door sheet metal near the B-pillar, a first curve of the compression of the abdominal ribs at the ribs of the simulated dummy and a second curve of the compression of the dummy chest at the dummy chest are extracted; According to the simulation analysis results of the door guard plate without a weakening curve, a third curve of the compression of the abdominal ribs at the ribs of the simulation dummy and a fourth curve of the compression of the dummy chest at the dummy chest are extracted; By comparing the first curve and the third curve, and the second curve and the fourth curve, it is determined that the front door guard plate with the weakened line has the effect of reducing the compression amount of the abdominal ribs.

10. A door guard having a weakening line, characterized in that: The arrangement is performed using the method for arranging a door panel weakening line as described in any one of claims 1 to 3.

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