CN111651857B - Method for designing rigidity of instrument panel - Google Patents
Method for designing rigidity of instrument panel Download PDFInfo
- Publication number
- CN111651857B CN111651857B CN202010330858.XA CN202010330858A CN111651857B CN 111651857 B CN111651857 B CN 111651857B CN 202010330858 A CN202010330858 A CN 202010330858A CN 111651857 B CN111651857 B CN 111651857B
- Authority
- CN
- China
- Prior art keywords
- instrument panel
- head
- windshield
- test
- model
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 53
- 238000012360 testing method Methods 0.000 claims abstract description 108
- 238000013461 design Methods 0.000 claims abstract description 51
- 239000011521 glass Substances 0.000 claims abstract description 39
- 206010019196 Head injury Diseases 0.000 claims abstract description 32
- 230000003116 impacting effect Effects 0.000 claims abstract description 14
- 238000004088 simulation Methods 0.000 claims description 77
- 230000001133 acceleration Effects 0.000 claims description 26
- 238000006073 displacement reaction Methods 0.000 claims description 21
- 238000012795 verification Methods 0.000 claims description 10
- 238000004364 calculation method Methods 0.000 claims description 7
- 238000011156 evaluation Methods 0.000 description 6
- 238000002474 experimental method Methods 0.000 description 6
- 238000010998 test method Methods 0.000 description 4
- 239000002131 composite material Substances 0.000 description 3
- 230000006378 damage Effects 0.000 description 3
- 208000027418 Wounds and injury Diseases 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000009863 impact test Methods 0.000 description 2
- 208000014674 injury Diseases 0.000 description 2
- 238000011002 quantification Methods 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000012938 design process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- -1 instrument panel Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M5/00—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M5/00—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings
- G01M5/0066—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings by exciting or detecting vibration or acceleration
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M7/00—Vibration-testing of structures; Shock-testing of structures
- G01M7/08—Shock-testing
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/15—Vehicle, aircraft or watercraft design
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Geometry (AREA)
- Aviation & Aerospace Engineering (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- General Engineering & Computer Science (AREA)
- Computational Mathematics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Automation & Control Theory (AREA)
- Instrument Panels (AREA)
Abstract
The invention provides a method for designing the rigidity of an instrument panel, which comprises the following steps: s1: performing a test of impacting the adult head model on the windshield glass, and acquiring initial speeds of impacting the adult head model on the instrument panel at positions with different distances between the windshield glass and the instrument panel; s2: and obtaining the maximum rigidity allowed by the instrument panel according to the preset head injury value of the instrument panel and the acquired initial speed. According to the method for designing the rigidity of the instrument panel, only the windshield glass is required to be tested to obtain the initial speed when the windshield glass is impacted against the instrument panel after the windshield glass is impacted down, and the maximum rigidity of the instrument panel is determined through the preset head injury value. The instrument panel part can be designed and intervened in the early stage according to the thought of forward design, and the risk of error in the later stage test is reduced.
Description
Technical Field
The invention relates to the field of automobile manufacturing, in particular to a method for designing the rigidity of an instrument panel.
Background
Since the new vehicle assessment procedures of 2021 and 2022 in china extend the range of pedestrian protection assessment from purely pedestrian to two-wheeled vehicle riders, the protection of such pedestrians by the vehicle dashboard is becoming increasingly important.
The protection of the instrument panel position of the domestic and foreign vehicles on pedestrians is always poor, and no good quantification method exists in how to design the instrument panel into a more friendly structure aiming at the requirement of pedestrian protection. The reason is that the pedestrian can strike the windshield before striking the instrument panel, and the striking speed of the head when the head passes through the windshield to reduce the speed and strike the instrument panel at different positions is difficult to obtain due to different positions of the windshield striking and different distances between the windshield and the instrument panel.
In addition, under the normal condition, as the impact instrument panel part of the head of the adult comprises automobile parts such as windshield glass, instrument panel, air conditioner air duct and the like, the simulation precision of CAE (Computer Aided Engineering ) is very low, the injury value information of each point can be obtained only by testing each point through a test, the design is difficult to intervene in advance, and the engineering boundary conditions are required to be proposed for the design; and the cost of the test is high, and each test point according to the evaluation rules of the new China needs to be tested.
Disclosure of Invention
The invention aims to solve the problem that the prior art lacks a quantification method for the design of the rigidity of an instrument panel aiming at the requirement of pedestrian protection. The method for designing the rigidity of the instrument panel is provided, only the windshield glass is required to be tested to obtain initial speeds when the windshield glass is impacted to different positions of the instrument panel after the windshield glass is impacted, the maximum rigidity of the instrument panel is limited through a preset head injury value, and the instrument panel part can be designed and intervened in the early stage according to the thought of forward design, so that the risk of error in the later stage test is reduced.
In order to solve the technical problems, the invention provides a method for designing the rigidity of an instrument panel, which comprises the following steps:
s1: an experiment of the adult head model impacting the windshield is performed, and the initial speed of the adult head model impacting the instrument panel at positions with different distances between the windshield and the instrument panel is obtained.
S2: obtaining the maximum rigidity allowed by the instrument panel according to the preset head injury value of the instrument panel and the acquired initial speed; the calculation formula of the maximum rigidity allowed by the instrument panel is as follows:
wherein: HIC represents a preset head injury value;
V 0 representing the initial velocity of an adult head model striking the instrument panel;
m represents the mass of the adult head model.
By adopting the scheme, through the test that the adult head model impacts the windshield glass, the initial speed that the adult head model impacts different positions of the instrument panel is obtained, the maximum allowed rigidity of the instrument panel is designed according to the preset head injury value, the instrument panel part can be designed and intervened in the early stage according to the forward design thought, and the risk of error in the later stage test is reduced.
According to another embodiment of the present invention, a method for designing stiffness of an instrument panel according to an embodiment of the present invention, a method for obtaining an initial velocity of an adult head model striking an instrument panel, includes: acquiring a head synthesized acceleration and time curve according to a test; integrating the head synthesized acceleration and time curve to obtain a head instantaneous speed and time curve; integrating the head instantaneous speed and time curve to obtain a head instantaneous displacement and time curve; fusing the head instantaneous speed and time curve and the head instantaneous displacement and time curve to obtain a head instantaneous speed and displacement curve; and acquiring the initial speed of the adult head model, which is impacted to the instrument panel, according to the head instantaneous speed and displacement curve.
By adopting the scheme, only one test is carried out on the windshield glass, and the curve of the instantaneous speed and the displacement of the head model of the adult can be obtained, so that the initial speed of all test points when the head model of the adult impacts the instrument panel after the head model of the adult impacts the windshield glass to reduce the speed is obtained, and the test cost is greatly reduced.
According to another embodiment of the present invention, a method for designing stiffness of an instrument panel is disclosed, wherein a distance between a windshield and an instrument panel is a distance from the windshield to the instrument panel measured in a direction of 65 degrees from a horizontal plane.
According to another specific embodiment of the invention, the method for designing the rigidity of the instrument panel disclosed by the embodiment of the invention is characterized in that the test point of the adult head model striking the windshield is the center of the windshield, and after the head synthetic acceleration is obtained, the initial speed of each test point is obtained through the standard windshield simulation model.
By adopting the scheme, the center of the windshield glass is selected as a test point, and the initial speed of each test point is obtained through a curve. The head instantaneous speed and displacement curve of each test point can be obtained more accurately through simulation calibration.
According to another embodiment of the present invention, the method for designing stiffness of an instrument panel disclosed in the embodiment of the present invention further includes: and after the standard windshield simulation model is subjected to verification test, testing at least two test points of the windshield simulation model, and verifying whether the standard meets the requirement. And when the standard is not satisfied, adjusting the design of the windshield simulation model, and again performing standard windshield simulation model.
By adopting the scheme, after the verification test is carried out on the standard windshield glass simulation model, an accurate simulation windshield glass model can be obtained, and the model can be used for acquiring the initial speed of each test point impacting the instrument panel and can also be used for the standard comparison of the whole vehicle simulation model. By adopting the scheme, the limitation on the rigidity of the instrument panel can be introduced in the initial stage of design, and the structure around each collision point can be accurately controlled by combining the simulated windshield model after calibration.
According to another embodiment of the invention, the method for designing the rigidity of the instrument panel disclosed by the embodiment of the invention comprises the step of arranging at least two test points at 1/4 area of two sides of the windshield glass simulation model along the length direction.
By adopting the scheme, the accuracy of CAE simulation is ensured, and the maximum rigidity allowed by the instrument panel determined by the initial speed of the head model of the adult impacting the instrument panel at different test positions is accurately acquired.
According to another specific embodiment of the invention, the method for designing the rigidity of the instrument panel disclosed by the embodiment of the invention is characterized in that the preset head injury value is obtained according to a pedestrian protection scoring strategy.
According to another embodiment of the present invention, the method for designing stiffness of an instrument panel disclosed in the embodiment of the present invention further includes: s3: performing a head impact instrument panel test, and checking an instrument panel simulation model to verify whether the rigidity of the instrument panel simulation model is greater than the maximum rigidity allowed by the instrument panel; and when the stiffness of the instrument panel simulation model is larger than the maximum stiffness allowed by the instrument panel, adjusting the design of the instrument panel simulation model, and performing the step S3 again.
By adopting the scheme, the design is closed loop by checking the simulation model of the instrument panel, particularly the structural hard points, and the maximum rigidity allowed by the instrument panel is corrected again, so that the situation that the rigidity of the instrument panel is increased sharply due to the structural hard points is avoided.
According to another embodiment of the present invention, the method for designing stiffness of an instrument panel disclosed in the embodiment of the present invention further includes: s4: when the rigidity of the instrument panel simulation model is not greater than the maximum rigidity allowed by the instrument panel, performing a pedestrian protection whole car collision test, and using the adult head model to strike the windshield glass and the instrument panel to obtain an actual head injury value; then, the whole vehicle simulation model is calibrated to obtain a predicted head injury value; and judging whether the error between the actual head injury value and the predicted head injury value is smaller than a preset error threshold value. When the error is smaller than a preset error threshold value, completing the design of the instrument panel; and when the error is not smaller than the preset error threshold, adjusting the design of the instrument panel, and performing the step S3 again.
By adopting the scheme, the pedestrian protection head is enabled to collide with the windshield and the instrument panel to form a design closed loop, the design cost is lower, and the probability of error verification is also greatly reduced.
According to another embodiment of the invention, the stiffness design method of the instrument panel disclosed by the embodiment of the invention has the preset error threshold value of 10%.
The beneficial effects of the invention are as follows:
according to the method for designing the rigidity of the instrument panel, through the test that the adult head model impacts the windshield glass, the initial speeds of the adult head model impacting different positions of the instrument panel are obtained, the maximum rigidity allowed by the instrument panel is designed according to the preset head injury value, the front-stage design and the intervention can be carried out on the instrument panel according to the thought of forward design, and the risk of error in the later-stage test is reduced.
Drawings
FIG. 1 is a flow chart of one embodiment of a method of designing instrument panel stiffness according to the present invention;
FIG. 2 is a flow chart of step S1 of the instrument panel stiffness design method of the present invention for obtaining the initial velocity of an adult head model striking an instrument panel
FIG. 3 is a flow chart of another embodiment of the instrument panel stiffness design method of the present invention, including steps S3, S4, and a target windshield simulation model step;
FIG. 4 is a schematic view of the instrument panel stiffness design method of the present invention for measuring distances from different test points of a windshield to an instrument panel;
FIG. 5a is a graph of G-t obtained from an adult head model impact windshield test in the instrument panel stiffness design method of the present invention;
FIG. 5b is a G-S curve obtained from an adult head model impact windshield test in the instrument panel stiffness design method of the present invention;
FIG. 6a is a G-t curve obtained from a CAE simulation of an adult head model striking a windshield in the instrument panel stiffness design method of the present invention;
FIG. 6b is a G-S curve obtained from a CAE simulation of an adult head model striking a windshield in the instrument panel stiffness design method of the present invention;
FIG. 7 is a graph comparing V-S curves obtained from an adult head model impact windshield test with V-S curves obtained from CAE simulation in the instrument panel stiffness design method of the present invention;
FIG. 8 is a schematic view of a windshield simulation model split region in the instrument panel stiffness design method of the present invention;
FIG. 9 is a schematic diagram of a head impact instrument panel simulation test in the instrument panel stiffness design method of the present invention.
Reference numerals illustrate:
100: an adult head model;
200: a windshield; 210: a center test point; 220:1/4 test area;
300: a dashboard;
400: a ball.
Detailed Description
Further advantages and effects of the present invention will become apparent to those skilled in the art from the disclosure of the present specification, by describing the embodiments of the present invention with specific examples. While the description of the invention will be described in connection with the preferred embodiments, it is not intended to limit the inventive features to the implementation. Rather, the purpose of the invention described in connection with the embodiments is to cover other alternatives or modifications, which may be extended by the claims based on the invention. The following description contains many specific details for the purpose of providing a thorough understanding of the present invention. The invention may be practiced without these specific details. Furthermore, some specific details are omitted from the description in order to avoid obscuring the invention. It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other.
It should be noted that in this specification, like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.
In the description of the present embodiment, it should be noted that the azimuth or positional relationship indicated by the terms "upper", "lower", "inner", "bottom", etc. are based on the azimuth or positional relationship shown in the drawings, or the azimuth or positional relationship in which the inventive product is conventionally put in use, are merely for convenience of describing the present invention and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific azimuth, be configured and operated in a specific azimuth, and therefore should not be construed as limiting the present invention.
The terms "first," "second," and the like are used merely to distinguish between descriptions and are not to be construed as indicating or implying relative importance.
In the description of the present embodiment, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present embodiment can be understood in a specific case by those of ordinary skill in the art.
For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.
Example 1
The invention provides a method for designing the rigidity of an instrument panel, which is shown in figure 1 and comprises the following steps:
s1: an experiment of the adult head model impacting the windshield is performed, and the initial speed of the adult head model impacting the instrument panel at positions with different distances between the windshield and the instrument panel is obtained.
Specifically, different countries or organizations have test methods for evaluating the head protection of pedestrians, and a test method can be selected for the adult head model impact windshield glass. The collision speed, angle, etc. parameters may be different for different experimental methods. The invention preferably adopts a test method in the evaluation rule of new China, the mass of the head model is 4.5kg, the collision speed is 40km/h, and the collision angle is 65 degrees; the distance of the windshield from the instrument panel is the distance from the windshield to the instrument panel measured at an angle of impact, e.g., 65 degrees, to the horizontal plane. The method of acquiring the initial velocity of the adult head model striking the instrument panel may be obtained by measurement by a measuring device or by calculation.
In general, an adult head model is required to select a test point on a windshield and strike the test point for a test of striking the windshield. For different test points or different impact angles on the windshield, the position of the final impact on the instrument panel may also be different, and the distance between the windshield and the instrument panel 300 may also be different, as shown in fig. 4, three different test points of the adult head model 100 impact the windshield 200, and finally impact different positions of the instrument panel 300, so that different distances d1, d2 and d3 are respectively obtained, and therefore, the initial speeds of the impact of the adult head model generated by the three test points on the instrument panel are different.
S2: obtaining the maximum rigidity allowed by the instrument panel according to the preset head injury value of the instrument panel and the acquired initial speed; the calculation formula of the maximum rigidity allowed by the instrument panel is as follows:
wherein: HIC represents a preset head injury value;
V 0 representing the initial velocity of an adult head model striking the instrument panel;
m represents the mass of the adult head model.
Specifically, the preset head injury value of the instrument panel is a head injury value limit value expected to be reached in an adult head model impact experiment when the instrument panel is designed, and generally, the high performance limit value of the head injury value is 1000, and the low performance limit value is 1350.
The head injury value (HIC) is defined as follows:
wherein: a is the head composite acceleration, which is the composite acceleration of the mass center of the head model, and can be obtained by a sensor in the head model of the adult, and the unit is g (1 g=9.81 m/s 2 )；t 1 、t 2 The initial and end moments of the adult head model impact are in s, respectively.
Defining an average acceleration:(V 0 the initial speed of striking the instrument panel is obtained; t: adult head model collision time) into HIC can be obtained:
instrument panel stiffness is defined as:
wherein: s represents the total displacement of the adult head model, and m represents the mass of the adult head model;
will beSubstituting the expression with t into k simplifies the maximum stiffness allowed by the available instrument panel:
by adopting the scheme, through the test that the adult head model impacts the windshield glass, the initial speed that the adult head model impacts different positions of the instrument panel is obtained, the maximum rigidity allowed by the instrument panel is designed according to the preset head injury value, the instrument panel part can be designed and intervened in the early stage according to the forward design thought, and the risk of error in the later stage test is reduced.
According to another embodiment of the present invention, as shown in fig. 2, a method for acquiring an initial velocity of an adult head model striking an instrument panel includes: acquiring a head synthesized acceleration and time curve according to a test; integrating the head synthesized acceleration and time curve to obtain a head instantaneous speed and time curve; integrating the head instantaneous speed and time curve to obtain a head instantaneous displacement and time curve; fusing the head instantaneous speed and time curve and the head instantaneous displacement and time curve to obtain a head instantaneous speed and displacement curve; and acquiring the initial speed of the adult head model, which is impacted to the instrument panel, according to the head instantaneous speed and displacement curve.
Specifically, a synthetic acceleration and time (G-t) curve of the gravity center position (COG) of an adult head model is obtained through an experiment of striking the adult head model against the windshield using a typical three-layer structure in which PVB (polyvinyl alcohol) films are disposed between upper and lower glass layers, for example, fig. 5a shows the G-t curve obtained according to the chinese new vehicle evaluation procedure experiment. Then the (V-t) curve of the instantaneous head velocity and time can be obtained by integrating the G-t curve, then the V-t curve can be integrated to obtain the instantaneous head displacement and time (S-t) curve, and finally the V-t curve and the S-t curve are fused, that is, the instantaneous displacement S is taken as the abscissa and the instantaneous velocity V is taken as the ordinate, so as to form the instantaneous head velocity and displacement (V-S) curve, and fig. 7 shows the V-S curve (test curve in the figure) obtained from the G-t curve of fig. 5 a. The initial impact speeds at different positions can be obtained by measuring the distances from different test points of the windshield to the instrument panel and substituting the distances into the V-S curve as shown in fig. 4.
By adopting the scheme, only one test is carried out on the windshield glass, and the curve of the instantaneous speed and the displacement of the head model of the adult can be obtained, so that the initial speed of all test points when the head model of the adult impacts the instrument panel after the head model of the adult impacts the windshield glass to reduce the speed is obtained, and the test cost is greatly reduced.
According to another embodiment of the invention, as shown in fig. 4, the distance of the windscreen from the instrument panel is measured from the windscreen to the instrument panel at an angle of 65 degrees to the horizontal.
The measurement method is determined according to the test method in the evaluation rule of new vehicles in China, and the collision angle of the head model is 65 degrees.
According to another embodiment of the invention, the test points of the adult head model striking the windshield are the center of the windshield, and after the head composite acceleration is obtained, as shown in fig. 3, the initial velocity of each test point is obtained by simulating the standard windshield.
Specifically, a software simulation model of a standard windshield glass is utilized, and automobile collision analysis software (ls-dyna software) can be used, and the process comprises the steps of establishing a windshield glass simulation model, simulating an adult head model impact windshield glass test, wherein the impact test point also selects the center of the windshield glass, obtaining a G-t curve in fig. 6a and a synthetic acceleration and head instantaneous displacement (G-S) curve in fig. 6b through CAE simulation, wherein the method for obtaining the G-S curve is to integrate the G-t curve to obtain a V-t curve, integrating the G-t curve and the S-t curve to obtain a G-S curve after integrating the G-t curve and the S-t curve. Comparing the G-t curve in fig. 5a obtained by the test of the actual adult head model against the windshield with the G-t curve obtained by CAE simulation in fig. 6a, requires that the actual HIC obtained by the test and the predicted HIC obtained by the simulation be within an allowable error range (10% recommended), wherein the actual HIC obtained in fig. 5a is 270.6 and the predicted HIC obtained in fig. 6a is 270.7, within the error range, and thus the actual HIC is comparable to the predicted HIC. Comparing the G-S curve in fig. 5b obtained by the test of the actual adult head model against the windshield with the G-S curve in fig. 6b obtained by CAE simulation, requires that the actual maximum crush distance of the adult head model obtained by the test and the predicted maximum crush distance obtained by the simulation be within an allowable error range (10% recommended), both the actual maximum crush distance obtained in fig. 5b and the actual maximum crush distance obtained in fig. 6b are about 140mm, within the error range, and thus the actual and predicted maximum crush distances are comparable.
And if the comparison meets the requirements and is within the error range, passing the comparison standard, and indicating that the windshield glass simulation model is qualified. The CAE simulated V-S curve is obtained according to the method shown as S1 in FIG. 2, and is compared with the V-S curve obtained by the test to obtain the comparison result shown as FIG. 7, the test V-S curve (test curve in the figure) is close to the simulated V-S curve (CAE curve in the figure), and the CAE simulated V-S curve should be located integrally above the tested V-S curve in consideration of the simulation effectiveness and engineering margin of the CAE. According to the measured distances from the head model of the adult to the instrument panel at different test points on the windshield, the initial speeds of different test points at different positions can be obtained through the V-S curve simulated by CAE.
If the actual HIC and the predicted HIC value are not in the allowable error range or the actual and predicted maximum collapse distance is not in the allowable error range, the standard is not passed, and the windscreen simulation model is not qualified; and adjusting parameters of the standard windshield simulation model, and performing standard windshield simulation model again.
The center of the windshield is selected as a test point, and the initial velocity of each test point is obtained through a curve, and although the accuracy is high at the center of the windshield, errors may occur at the periphery of the windshield. By adopting the scheme, a more accurate head instantaneous speed and displacement curve of each test point can be obtained through simulation calibration, and a qualified windshield glass simulation model can be obtained for subsequent tests.
According to another embodiment of the present invention, as shown in fig. 3, the method further comprises: and after the standard windshield simulation model is subjected to verification test, testing at least two test points of the windshield simulation model, and verifying whether the standard meets the requirement. And when the standard is not satisfied, adjusting the design of the windshield simulation model, and again performing standard windshield simulation model.
Specifically, after the center of the windshield glass simulation model is used as a test point mark, at least one test point is selected from the areas on two sides of the center of the windshield glass simulation model along the length direction (y direction) to be verified in a simulation mode, the test process is similar to that of the impact center part, a G-S curve is obtained after the G-t curve of the adult head model is obtained, then the G-t curve and the G-S curve obtained in the verification test are compared with the G-t curve and the G-S curve obtained in the CAE simulation, and if the comparison error of the HIC and the maximum crumple distance of the CAE simulation and the comparison error of the HIC and the maximum crumple distance of the verification is within an allowable error range of 10%, the comparison mark is considered to meet the requirements.
By adopting the scheme, after the verification test is carried out on the standard windshield glass simulation model, an accurate simulation windshield glass model can be obtained, and the model can be used for acquiring the initial speed of each test point impacting the instrument panel and can also be used for the standard comparison of the whole vehicle simulation model. By adopting the scheme, the limitation on the rigidity of the instrument panel can be introduced in the initial stage of design, and the structure around each collision point can be accurately controlled by combining the simulated windshield model after calibration.
According to another embodiment of the invention, the at least two test points are two points located in 1/4 of the area on each side of the windscreen phantom in the length direction.
Specifically, as shown in fig. 8, the windshield 200 is cut into 4 areas (the broken line separation areas in the figure) at equal intervals along the length direction, i.e., the y direction, the center test point 210 is in the middle two test areas, and the crack can completely propagate around due to the fact that the center area is far away from the a column; however, since the two 1/4 test areas 220 on both sides in the y direction are close to the a pillar, the crack is affected by the a pillar, so in order to ensure the accuracy of CAE simulation and accurately obtain the maximum rigidity allowed by the instrument panel determined by the initial velocity of the adult head model striking the instrument panel at different test positions, it is necessary to select additional test points in the 1/4 test areas 220 on both sides in the y direction.
According to another embodiment of the present invention, as shown in fig. 1 and 3, the preset head injury value is obtained according to a pedestrian protection score policy.
Specifically, the pedestrian protection score strategy refers to that in the design process of an instrument panel, a specific design is performed according to the predicted pedestrian protection score in order to ensure the safety of pedestrians. The pedestrian protection score is specifically a head model score, collision points can be uniformly distributed in a test area by a grid point method, and the pedestrian protection score is obtained through calculation of the overall score rate of the collision points; the score is determined according to HIC, and thus, the preset head injury value for each region can be obtained according to the designed score.
According to another embodiment of the present invention, as shown in fig. 3, the method further comprises: s3: performing a head impact instrument panel test, and checking an instrument panel simulation model to verify whether the rigidity of the instrument panel simulation model is greater than the maximum rigidity allowed by the instrument panel; and when the stiffness of the instrument panel simulation model is larger than the maximum stiffness allowed by the instrument panel, adjusting the design of the instrument panel simulation model, and performing the step S3 again.
Specifically, the instrument panel is designed according to the maximum allowable stiffness of the instrument panel obtained in the step S2, and the head impact instrument panel test is carried out first, specifically, a ball with the diameter of 165mm and the mass of 6.8kg is used for impacting the instrument panel at an initial speed of 6.8m/S and an angle of 65 DEG with the horizontal plane, and the acceleration within the range of 80mm of the ball intrusion is obtained according to the test, wherein the acceleration is required to be less than 40g, and the rigidity of the impact test point of the instrument panel is indicated to be less than the allowable maximum rigidity. After the test, a simulated model of the instrument panel was calibrated, as shown in FIG. 9, using ls-dyna software to build a simulated model of the instrument panel, simulating a head impact instrument panel test, with a ball 400 impacting the panel of instrument panel 300 at an initial velocity of 6.8m/s at 65 ° to the horizontal plane, the impact obtaining acceleration of ball 400 within the range of 80 mm. If the acceleration obtained by CAE simulation and test is less than 40g, the comparison error is within the allowable error range such as 10%, and the maximum acceleration of CAE simulation is less than the test value, the comparison standard is considered to meet the requirement; otherwise, adjusting the simulation model of the instrument panel to continue the calibration.
The reason for the above test conditions is that some laboratories cannot provide a rigid head form of 4.5kg and cannot provide a low initial velocity of 8.36m/s, and the initial velocity needs to be reduced by increasing the mass of the head form to meet the laboratory requirements when performing the head impact instrument panel test.
The reason for defining the above conditions is that, as can be seen from the V-S diagram in FIG. 5, the maximum crush distance of the adult head model is 140mm without the instrument panel, and the corresponding energy of 6.8kg, 6.8m/S rigid sphere is equivalent to that of 4.5kg, 8.36m/S adult head model, calculated asSubstituting an initial velocity of 8.36m/S into the V-S curve of fig. 5 finds that the corresponding windshield to dashboard distance is around 60mm, in which case the adult head model potentially still remains 140mm-60mm = 80mm of crush, which is the amount of deformation that the dashboard potentially deforms, and the maximum stiffness allowed by the dashboard needs to be within 80mm to meet the requirements.
Further, HIC obtained from the calculation formula of HIC and the head impact glass was 270, and the average acceleration of the head impact glass wasThen the maximum HIC of not more than (50.4+40) can be obtained by superposing the acceleration of 40g at maximum provided by the instrument panel 2. *0.015 1164, and the injury value is 1000. Ltoreq. HIC<Within 1350, therefore, at least 0.50 points can be obtained at the time of pedestrian protection evaluation, which score target is reasonable for the windshield area.
Further, since the average acceleration is defined in the above maximum stiffness calculation formula, that is, the undesired acceleration fluctuates greatly during the collision, for example, the instantaneous acceleration deviates too much from the average acceleration due to hard spots in the 80mm crush space, in this case, a relatively large error occurs in the maximum stiffness allowed by the obtained instrument panel, and it is defined that the stiffness of the instrument panel is uniformly distributed in the 80mm crush space and is lower than the maximum stiffness allowed by the instrument panel.
After the standard is satisfied, other test points are selected, and particularly, some structural hard points of the instrument panel, such as mounting points of the instrument panel, air outlets of air conditioners and the like, are selected to verify whether the rigidity of the instrument panel simulation model is larger than the maximum rigidity allowed by the instrument panel. And the instrument panel model meeting the CAE simulation requirement can be used for the final whole vehicle simulation standard.
Through steps S1 and S2, while it is possible to obtain a dashboard that allows maximum stiffness limiting the dashboard stiffness, there are inevitable structural hard spots at certain locations of the dashboard that tend to give rise to momentary increases in adult head acceleration. By adopting the scheme, the maximum rigidity of the instrument panel is verified by the standard, and the structural hard point of the instrument panel is checked, so that the design is closed-loop, the maximum rigidity allowed by the instrument panel is corrected again, and the condition that the rigidity of the instrument panel is increased sharply due to the structural hard point is avoided. Meanwhile, the damage value (HIC) of the adult head model is controlled in the product design stage, so that the problem is prevented from being found only in the whole vehicle test stage in the later design stage.
According to another embodiment of the present invention, as shown in fig. 3, the method further comprises: s4: when the rigidity of the instrument panel simulation model is not greater than the maximum rigidity allowed by the instrument panel, performing a pedestrian protection whole car collision test, and using the adult head model to strike the windshield glass and the instrument panel to obtain an actual head injury value; then, the whole vehicle simulation model is calibrated to obtain a predicted head injury value; and judging whether the error between the actual head injury value and the predicted head injury value is smaller than a preset error threshold value. When the error is smaller than a preset error threshold value, completing the design of the instrument panel; and when the error is not smaller than the preset error threshold, adjusting the design of the instrument panel, and performing the step S3 again.
Specifically, the standard whole vehicle simulation model can also use ls-dyna software, the instrument panel finished by the standard in the step S3 is assembled, and if the standard windshield simulation model is carried out in the step S1, the windshield finished by the standard can be assembled at the same time, the G-t curve obtained through the adult head model impact windshield test and the G-S curve obtained through the standard whole vehicle simulation model and the HIC obtained through integration are compared, and if the error of the actual HIC and the predicted HIC value is within a preset error threshold value such as 10%, the standard of the whole vehicle is successfully finished, and the design is finished. By adopting the scheme, the pedestrian protection head is enabled to collide with the windshield and the instrument panel to form a design closed loop, the design cost is lower, and the probability of error verification is also greatly reduced.
According to another embodiment of the invention, the preset error threshold is 10%.
Specifically, according to the rule of evaluation of new vehicles in China, the HIC value of the verification test allows 10% deviation from top to bottom due to test uncertainty, and is used for verifying the correctness of prediction. So that a design can be considered to meet the requirements within 10%.
While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing is a further detailed description of the invention with reference to specific embodiments, and it is not intended to limit the practice of the invention to those descriptions. Various changes in form and detail may be made therein by those skilled in the art, including a few simple inferences or alternatives, without departing from the spirit and scope of the present invention.
Claims (7)
1. A method of designing stiffness of an instrument panel, comprising:
s1: performing an adult head model impact windshield test, and acquiring initial speeds of the adult head model impacting the instrument panel at positions with different distances between the windshield and the instrument panel, wherein the method for acquiring the initial speeds comprises the following steps:
acquiring a head synthesized acceleration and time curve according to the test;
integrating the head synthesized acceleration and time curve to obtain a head instantaneous speed and time curve;
integrating the head instantaneous speed and time curve to obtain a head instantaneous displacement and time curve;
fusing the head instantaneous speed and time curve and the head instantaneous displacement and time curve to obtain a head instantaneous speed and displacement curve;
acquiring the initial speed of the adult head model impacting the instrument panel according to the head instantaneous speed and displacement curve;
s2: obtaining the maximum rigidity allowed by the instrument panel according to the preset head injury value of the instrument panel and the acquired initial speed; wherein the method comprises the steps of
The calculation formula of the maximum rigidity allowed by the instrument panel is as follows:
wherein: HIC represents the preset head injury value;
V 0 representing the initial velocity of an adult head model striking the dashboard;
m represents the mass of the adult head model;
s3: performing a head impact instrument panel test, and checking an instrument panel simulation model to verify whether the stiffness of the instrument panel simulation model is greater than the maximum stiffness allowed by the instrument panel;
when the rigidity of the instrument panel simulation model is larger than the maximum rigidity allowed by the instrument panel, adjusting the design of the instrument panel simulation model, and performing step S3 again;
s4: when the rigidity of the instrument panel simulation model is not greater than the maximum rigidity allowed by the instrument panel, performing a pedestrian protection whole vehicle collision test, and using the adult head model to strike the windshield glass and the instrument panel to obtain an actual head injury value; then, the whole vehicle simulation model is calibrated to obtain a predicted head injury value; judging whether the error between the actual head injury value and the predicted head injury value is smaller than a preset error threshold value or not;
when the error is smaller than a preset error threshold value, completing the design of the instrument panel;
and when the error is not smaller than a preset error threshold, adjusting the design of the instrument panel, and performing step S3 again.
2. The instrument panel stiffness design method of claim 1, wherein the distance from the windshield to the instrument panel is a distance from the windshield to the instrument panel measured at an angle of 65 degrees to a horizontal plane.
3. The instrument panel stiffness design method of claim 2, wherein the test point of the adult head model striking the windshield is the center of the windshield, and the initial velocity of each test point is obtained by simulating the standard windshield after the head resultant acceleration is obtained.
4. A method of designing stiffness of an instrument panel as recited in claim 3, further comprising:
after a standard windshield glass simulation model is subjected to verification test, testing at least two test points of the windshield glass simulation model, and verifying whether the standard meets the requirement;
and when the standard is not satisfied, adjusting the design of the windshield simulation model, and again calibrating the windshield simulation model.
5. The instrument panel stiffness design method of claim 4, wherein the at least two test points are two points located in 1/4 area on both sides of the windshield simulation model in the length direction, respectively.
6. The instrument panel stiffness design method of claim 1, wherein the preset head injury value is obtained according to a pedestrian protection scoring strategy.
7. The instrument panel stiffness design method of claim 1, wherein the preset error threshold is 10%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010330858.XA CN111651857B (en) | 2020-04-24 | 2020-04-24 | Method for designing rigidity of instrument panel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010330858.XA CN111651857B (en) | 2020-04-24 | 2020-04-24 | Method for designing rigidity of instrument panel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111651857A CN111651857A (en) | 2020-09-11 |
| CN111651857B true CN111651857B (en) | 2023-12-26 |
Family
ID=72344450
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010330858.XA Active CN111651857B (en) | 2020-04-24 | 2020-04-24 | Method for designing rigidity of instrument panel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111651857B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112651161B (en) * | 2020-12-29 | 2023-01-13 | 上汽大众汽车有限公司 | Rigidity calibration method based static head collision simulation method for automobile instrument panel suspension screen |
-
2020
- 2020-04-24 CN CN202010330858.XA patent/CN111651857B/en active Active
Non-Patent Citations (1)
| Title |
|---|
| 刘奇等.行人头部冲击载荷下风挡玻璃的模拟和试验验证.《汽车安全与节能学报》.2011,第第2卷卷(第第2期期),第128-133页. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111651857A (en) | 2020-09-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Mohammed et al. | Evaluation of automotive hood and bumper performance with composite material by pedestrian impactor systems | |
| CN105676449B (en) | Outside rear-view mirror view verification method and device | |
| CN111651857B (en) | Method for designing rigidity of instrument panel | |
| CN106441941A (en) | Evaluation method and device of automobile front collision performance | |
| CN111832120A (en) | Visual field checking method and visual field checking system for automobile outer rearview mirror | |
| JP4752009B2 (en) | Minimum distance calculation method, pedestrian protection test line creation method, program, design support apparatus, and recording medium | |
| CN109141913B (en) | A kind of body of a motor car installation reliability test method | |
| CN110823587B (en) | Side collision trolley test method | |
| CN102463570B (en) | Marking device for pedestrian protection test | |
| Chen et al. | Optimized AHSS structures for vehicle side impact | |
| CN112129543A (en) | Method for testing side parking performance of automatic driving vehicle | |
| CN112651161B (en) | Rigidity calibration method based static head collision simulation method for automobile instrument panel suspension screen | |
| CN207163621U (en) | A kind of car door cover plate dropout force detection system | |
| JP4525627B2 (en) | Shape data processing method and pedestrian protection test line creation method | |
| CN105701301B (en) | Automobile positive crash tests method and device | |
| Lin et al. | A study of finite element modeling for simulation of vehicle rollover | |
| Mohd Isa et al. | New car assessment program for southeast asian countries: Current status and future developments | |
| CN112580201A (en) | Simulation test evaluation method and evaluation system for vehicle emergency steering auxiliary system | |
| CN109263653B (en) | Method for confirming front view angle of automobile driver | |
| KR102179442B1 (en) | Vehicle and controlling method of the vehicle | |
| Zhao et al. | Whole car side impact mode and response evaluation | |
| KR102526015B1 (en) | Method for analyzing stiffness change of vehicle front frame before and after accident repair and method for evaluating safety of repaired vehicle using thereof | |
| CN106055781A (en) | Plastic part automatic damage assessment system and plastic part automatic damage assessment method based on automobile collision CAE technology | |
| CN114462150A (en) | Virtual calibration method for automobile safety airbag controller and vehicle | |
| Kim et al. | Interpretation of stiffness change over the trunk side of a vehicle upon a re-accident after repair its former rear impact collision accident |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |