CN113704865A

CN113704865A - Crash-proof analysis method for main transmission path bearing component of composite material reinforced whole vehicle

Info

Publication number: CN113704865A
Application number: CN202110798834.1A
Authority: CN
Inventors: 徐莉; 邬杰; 徐鸣涛; 陈冬民; 袁杰
Original assignee: Jiangling Motors Corp Ltd
Current assignee: Jiangling Motors Corp Ltd
Priority date: 2021-07-15
Filing date: 2021-07-15
Publication date: 2021-11-26

Abstract

The invention relates to a crash-proof analysis method for a main transmission path force-bearing component of a composite material reinforced whole vehicle, which is characterized in that a crash test is carried out on a body-in-white in a basic state; acquiring body-in-white collision data of a basic state; the vehicle body is designed with light structure, and a vehicle body collision test is carried out; determining a weak part of a vehicle body according to collision data, adding a composite material reinforcing member to the weak part of the vehicle body, and adjusting the structural design of a lap joint area; performing a vehicle body collision test; and ensuring that the vehicle body collision data meets the design target, and finishing the design target of vehicle body light weight. The method for analyzing the crashworthiness of the main transmission path bearing component of the composite material reinforced whole automobile comprehensively considers the design of material lightweight and structural lightweight, and realizes the lightweight of the automobile body of the automobile on the premise of controllable cost and no influence on the existing manufacturing process.

Description

Crash-proof analysis method for main transmission path bearing component of composite material reinforced whole vehicle

Technical Field

The invention relates to an analysis method for the crashworthiness of an automobile, in particular to an analysis method for the crashworthiness of a main transmission path bearing component of a composite material reinforced whole automobile.

Background

The lightweight automobile body structure is a high hot topic in the industry in recent years, and concepts such as an all-aluminum automobile body, a plastic instead of steel, a carbon fiber composite material, a glass fiber reinforced material and the like are diversified. Although products derived from the advanced lightweight concept have the advantages of light weight, corrosion resistance and the like, the products have the problems of complicated manufacturing process, high cost, difficulty in recycling of thermosetting materials and the like, and the wide-range application of the products is limited. At present, the most widely applied glass fiber reinforced composite materials are also mostly distributed at the parts with lower load stress of automobiles, such as 'plastic tail doors' and 'plastic fenders'.

Mainstream methods for designing light-weight automobile bodies include material light-weight design and structural light-weight design. The development and application of material technology promote the design, manufacture and application of industrial products, and nowadays, composite materials are the main research targets, and the quality of the whole automobile is reduced by using the design of materials, so that the composite materials can be used for replacing some metal materials. The design of light structure, the development of the analysis technology of the crashworthiness of the automobile body structure in the finite element theory, and the application of the analysis technology of the crashworthiness in the automobile industry greatly facilitate the design link and improve the design efficiency.

Factors such as safety, comfort, light weight and informatization of automobiles become important references for selecting automobiles for consumers. The lightweight of automobile body makes the driver more be convenient for control the car, has increased the operating stability. Meanwhile, among factors influencing the oil consumption of the automobile, the light weight of the automobile body is particularly remarkable, the fuel consumption can be greatly reduced, and the method is one of the most effective means for meeting the national energy-saving and emission-reducing regulation requirements. However, the lightweight of the vehicle body brings about problems of safety and crashworthiness, and the capability of the main force bearing part of the vehicle body to resist deformation when the automobile is impacted determines whether the passenger compartment has enough living space.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the crashworthiness analysis method for the composite material reinforced complete vehicle main transmission path bearing member, which adopts the composite material reinforced member to realize the light weight of the vehicle body on the premise of controllable cost and no influence on the existing manufacturing process.

The technical scheme adopted by the invention is as follows:

a crash-proof analysis method for a load-bearing component of a main transmission path of a composite material reinforced whole vehicle comprises the following steps:

step 1, starting;

step 2, carrying out a crash test on the white body in the basic state;

step 3, acquiring body-in-white collision data of a basic state;

step 4, judging whether the vehicle body collision data meet the design target; the collision data satisfies the design objective, step 5 is performed, the collision data fails to satisfy the design objective, step 7 is performed,

step 5, carrying out structure lightweight design on the vehicle body, and carrying out vehicle body collision test;

step 6, judging whether the vehicle body collision data meet the design target after the structure is designed in a light weight way; the collision data satisfies the design objective, step 5 is performed, the collision data fails to satisfy the design objective, step 7 is performed,

step 7, adding a CBS component at the weak part of the vehicle body, and adjusting the structural design of the lap joint area; performing a vehicle body collision test;

step 8, judging whether the vehicle body collision data meets the design target after the CBS component is added; step 9 is executed when the collision data meets the design target, and step 7 is executed when the collision data cannot meet the design target;

step 9, completing CBS structural member design and crashworthiness analysis, storing data and completing the aim of vehicle body lightweight design;

and step 10, ending.

Preferably, the crash data failing to satisfy the design target means that the design of the vehicle body structure is excessive for weight reduction, and it is necessary to extract the section load bearing value and the stress concentration collapse position on all paths from the crash resistance analysis result.

Preferably, the reinforcing support member is provided at a vehicle body concentrative collapse position.

Preferably, the stress concentration collapse location is added to the composite reinforcement member, requiring different composite reinforcement member designs and their location distributions to be tried.

Preferably, the reinforced support member material is: composite materials, engineering plastics, carbon fibers, glass fibers, steel, aluminum alloy and aluminum magnesium alloy.

Preferably, the main bearing member is a vehicle B column, the vehicle B column is designed in a light weight mode, and the implementation steps of increasing the composite material reinforcing member at the weak position of the vehicle B column to recover the original roof compressive strength of the whole vehicle are as follows:

(1) carrying out top compression resistance and crashworthiness analysis on the whole vehicle in the basic state; (2) acquiring the analysis result of the compression resistance and the collision resistance in the step 3, judging whether the result meets the design target, and optimizing the B-pillar structure metal plate if the result meets the design target;

the B post structure panel beating includes: the thicknesses of the ceiling vertical beam 1, the side wall upper edge beam 2, the B column upper inner plate 3, the B column reinforcing plate 4, the B column lower inner plate 5 and the B column torsion reinforcing plate 6 are greatly reduced;

until the test result of the top compression and crashworthiness does not meet the design target; (3) in order to meet the requirement of top compressive strength, section bearing force values and stress concentration collapse positions on all paths are extracted from the analysis result of crashworthiness, a composite material reinforcing member is added in the region, the analysis result of the top compressive crashworthiness meets the performance level before light weight, and the optimization design is completed.

Compared with the prior art, the invention has the beneficial effects that:

the crash resistance analysis method of the composite material reinforced complete vehicle main transmission path bearing member comprehensively considers the material lightweight and structure lightweight design, and can realize the lightweight scheme of the composite material reinforced member to be widely applied to the main bearing part of the vehicle load on the premise of controllable cost and no influence on the existing manufacturing process.

The invention relates to a crash-proof analysis method for a composite material reinforced complete vehicle main transmission path bearing component. Meanwhile, the component is controllable in cost, simple in manufacturing process and easy to install, and plays a significant role in the light weight design of the vehicle body.

Drawings

FIG. 1 is a schematic flow chart of a crash resistance analysis method for a load-bearing component of a main transmission path of a composite material reinforced whole vehicle;

FIG. 2 is a schematic diagram comparing crash resistance analysis results of a crash resistance analysis method for a main transmission path force-bearing member of a composite material reinforced whole vehicle with a loading force and displacement curve diagram, and the crash resistance analysis results are obtained through CAE simulation based on GB26134 regulation loading requirements; wherein, the curve 1 is a top pressure strength loading curve of a basic state before light weight, the curve 2 is a top pressure strength loading curve after light weight, and the curve 3 is a top pressure strength loading curve after a composite material reinforcing member is added in a local weak area after light weight, so that the same safety performance as before light weight is met;

FIG. 3 is a schematic diagram of the crash resistance analysis method of a main transmission path force-bearing component of a composite material reinforced whole vehicle based on GB26134 regulation on loading of the whole vehicle;

FIG. 4 is a B-pillar sheet metal structure schematic diagram of a crash resistance analysis method for a main transmission path force-bearing component of a composite material reinforced whole vehicle;

fig. 5 is a structural schematic diagram of a B-pillar added with a composite material reinforcing member in a crash resistance analysis method of a main transmission path force-bearing member of a composite material reinforced vehicle.

Detailed Description

The invention is described in detail below with reference to the figures and examples:

as shown in the attached figures 1-5, the crash resistance analysis method of the main transmission path bearing component of the composite material reinforced whole vehicle comprises the following steps:

step 1, starting;

step 2, carrying out a crash test on the white body in the basic state; the crash test mainly refers to that a rigid flat plate is used for pressing the top of a vehicle downwards at a constant speed in a slant way as shown in figure 3, and the crash condition that the vehicle is rolled by a heavy object in a traffic accident is simulated.

Step 3, acquiring body-in-white collision data of a basic state;

step 4, judging whether the vehicle body collision data meet the design target; step 5, if the collision data meet the design target, the collision data cannot meet the design target, and step 7 is executed;

the design target refers to a certain amount exceeding the requirements of the regulations, the invention relates to the GB26134 passenger car roof compression strength, and the requirements of the regulations range from: the loading load is 3.0 times of the vehicle service mass, and the moving amount of the lower surface of the loading device is not more than 127 mm. Taking the vehicle servicing mass as 1.6T as an example, the design objective referred to in the present invention is defined as: the loading load is more than or equal to 56448N, and the moving amount of the lower surface of the loading device is less than or equal to 127 mm;

f = 3M a K, where F refers to the load, M is the vehicle trim mass, a is the acceleration of gravity, and K is the design target safety factor. 56448N =1600Kg 9.8m/s²*3*1.2。

Step 5, carrying out structure lightweight design on the vehicle body, and carrying out vehicle body collision test; on the premise of meeting the step 4, that is, the movement amount of the lower surface of the loading device can still be ensured to be smaller than 127mm even if the loading load exceeds 56448N, which indicates that the design margin of the vehicle body structure exists, and from the viewpoint of energy saving, a designer will perform corresponding lightweight work, generally refers to selecting a beam system structural member on the vehicle body to perform overall thinning, taking the invention as an example, three

metal pieces

3, 4 and 6 shown in fig. 4 can be thinned from 1.8mm to 1.4 mm.

Step 6, judging whether the vehicle body collision data meet the design target after the structure is designed in a light weight way; the collision data meets the design target, step 5 is executed, the collision data cannot meet the design target, step 7 is executed to judge the result of step 5, namely after the three

metal parts

3, 4 and 6 shown in fig. 4 are thinned to 1.4mm, the loading load F is possibly smaller than 56448N (the design target is that the loading load is larger than or equal to 56448N), at the moment, step 7 needs to be executed, and the lightweight scheme of the composite material reinforcing member is applied to the load main bearing part shown in fig. 4 on the premise that the cost is controllable and the existing manufacturing process is not influenced.

Step 7, adding a CBS component at the weak part of the vehicle body, and adjusting the structural design of the lap joint area; performing a vehicle body collision test; adjusting the structural design of the lap joint area, namely, after 3, 4 and 6 in the figure 4 are integrally thinned, adding CBS components in the areas of the

joint positions

2 and 3 to change the design into the design shown in the figure 5;

and (3) completing crashworthiness analysis: 1. establishing a body-in-white finite element model; 2. welding the model by referring to the real object; 3. setting an initialization state, calculating boundary conditions, a loading mode and parameters needing to be output, and 4, calculating whether the CBS structural member design can reach a loading load F which is more than or equal to 56448N by adopting an LS-DANY solver.

And step 10, ending.

The crash data which cannot meet the design target means that the design of the vehicle body structure is excessive in light weight, namely, the material or thickness of the vehicle body structure part is excessively reduced, so that the loading load F is less than 56448N, and the section bearing force values and the stress concentration collapse positions on all paths need to be extracted from the crash resistance analysis result. The extraction method comprises the following steps: and (3) adopting finite element calculation post-processing software, reading the loading force value of the loading device and the strain values of all parts in the invention in the software, and if the strain values exceed the strain limit of the material of the part, determining that the position of the part is collapsed. The strain limit of the material can be searched according to a material manual, and can also be obtained through a static tensile test.

The reinforcing support member is disposed at a vehicle body concentrated collapse position.

The addition of composite reinforcement members at stress concentration collapse locations requires different composite reinforcement member designs and their location distributions to be tried.

The reinforced support member material is: composite materials, engineering plastics, carbon fibers, glass fibers, steel, aluminum alloy and aluminum magnesium alloy.

The main transfer path load-bearing component of whole car includes: longitudinal beams, transverse beams, threshold beams, A/B/C/D upright columns and the like.

The invention provides a composite material reinforced member, which comprises an engineering framework and a thermal expansion structure adhesive, wherein the member is arranged in a cavity of a vehicle body bearing part, and has enough strength to resist deformation and ensure the living space of passengers when the vehicle body is extruded by the outside. Meanwhile, the component is controllable in cost, simple in manufacturing process and easy to install, and plays a significant role in the light weight design of the vehicle body.

In the specific embodiment, after the B pillar of a certain vehicle type is lightened, the actual design case of the original roof compressive strength of the whole vehicle is recovered by adding the composite material reinforcing member at the weak position: (1) the top compression and crashworthiness analysis is carried out on the whole vehicle in the basic state, and the curve of the loading force and the displacement is shown as a curve 1 in fig. 2.

(2) Obtaining the analysis result of step 3, curve 1 in fig. 2, and determining whether the result meets the design objective, which generally means exceeding the regulatory requirementThe design rule of the invention is GB26134 passenger car roof compression strength, and the required range of the rule is as follows: the loading load is 3.0 times of the vehicle service mass, and the moving amount of the lower surface of the loading device is not more than 127 mm. Taking the vehicle servicing mass as 1.6T as an example, the design objective referred to in the present invention is defined as: the loading load is more than or equal to 56448N, and the moving amount of the lower surface of the loading device is less than or equal to 127 mm. F = 3M a K, where F refers to the load, M is the vehicle trim mass, a is the acceleration of gravity, and K is the design target safety factor. 56448N =1600Kg 9.8m/s²*3*1.2. If so, optimizing the B-pillar structure metal plate shown in the figure 4; the B post structure panel beating includes: the thicknesses of the ceiling upright beam 1, the side wall upper edge beam 2, the B column upper inner plate 3, the B column reinforcing plate 4, the B column lower inner plate 5 and the B column torsion reinforcing plate 6 are greatly reduced until the test result of the top compression resistance and collision resistance does not meet the design target, and the analysis result of the top compression resistance and collision resistance is shown as a curve 2 in fig. 2.

(3) In order to meet the requirement of top compressive strength, section bearing force values and stress concentration collapse positions on all paths are extracted from the analysis result of crashworthiness, and a composite material reinforcing member 7 is added in the region, as shown in fig. 5, and the analysis result of the top compressive crashworthiness is shown as a curve 3 in fig. 2, so that the performance level before weight reduction is met.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the structure of the present invention in any way. Any simple modification, equivalent change and modification of the above embodiments according to the technical spirit of the present invention are within the technical scope of the present invention.

Claims

1. The method for analyzing the crashworthiness of the automobile composite material reinforced main bearing component is characterized by comprising the following steps of:

step 1, starting;

step 2, carrying out a crash test on the white body in the basic state;

step 3, acquiring body-in-white collision data of a basic state;

and step 10, ending.

2. The crash resistance analysis method for the automobile composite material reinforced main bearing member as recited in claim 1, characterized in that:

the crash data failing to satisfy the design target means that the design of the vehicle body structure is excessive in weight, and it is necessary to extract the section bearing force values and the stress concentration collapse positions on all paths from the crash resistance analysis result.

3. The crash resistance analysis method for the automobile composite material reinforced main bearing member as recited in claim 1, characterized in that:

4. The crash resistance analysis method for the automobile composite material reinforced main bearing member as recited in claim 1, characterized in that:

5. The crash resistance analysis method for the automobile composite material reinforced main bearing member as recited in claim 1, characterized in that:

6. The crash resistance analysis method for the automobile composite material reinforced main bearing member as recited in claim 1, characterized in that: the main bearing component is a vehicle B column, and the lightweight design of the vehicle B column is implemented by adding a composite material reinforcing component at a weak position to restore the original roof compressive strength of the whole vehicle, and comprises the following steps:

(1) carrying out top compression resistance and crashworthiness analysis on the whole vehicle in the basic state;

(2) acquiring the analysis result of the compression resistance and the collision resistance in the step 3, judging whether the result meets the design target, and optimizing the B-pillar structure metal plate if the result meets the design target; until the test result of the top compression and crashworthiness does not meet the design target;

(3) in order to meet the requirement of top compressive strength, section bearing force values and stress concentration collapse positions on all paths are extracted from the analysis result of crashworthiness, a composite material reinforcing member is added in the region, the analysis result of the top compressive crashworthiness meets the performance level before light weight, and the optimization design is completed.