Designing And Calibration Research For Dummy Chest Of The Automobile Obverse Impacting

Collision test is a basic and important test to check and evaluate the capability of passive safety protection.The equipment to test and obtain the results of the collision damage is often personified as a collision dummy,or a dummy.As one of the necessary testing equipment in the crash test,the dummy plays an important and unreplaceable role in improving the safety of vehicles.The dummy dose not only have similar size and form as a real occupant,but also simulate the response of a real occupant in a crash test.In an impact test,the kinematic and dynamic response of a dummy to the shock excitation is obtained.For a long time,this kind of dummy collision test equipment used in our country is monopolized by a foreign enterprise.The cost of this kind of foreign crash dummy and its supplies are extremely expensive,ordinary car companies can not buy many sets,They are used and maintained carefully.This greatly limits the development of automotive safety research in China.At the same time,China has not had any certificated dummy product produced by an international enterprise,so the dummy product is still blank in China.Therefore,it is of great significance to improve the level of vehicle passive safety and reduce the cost of passive safety assessment by developing the dummy to fill the blank in the field of dummy research.The topic of this paper comes from the cooperative research project of the author’s research group and a domestic automobile technology institute.In the process of vehicle passive safety test,a main impact is the direct damage to the occupant’s chest.Therefore,it is very important to analyze and discuss the design of a dummy structure,material to produce a dummy and so on.This paper focuses on how to reproduce the process of car crash and the damaging process suffered by the occupants.To study the design of simulated dummy,especially the chest structure,the main work of this paper is as follows:(1)In order to design more reasonable "anthropomorphic" dummy chest model the chest injury theory and frontal chest model is studied,Maxwell model is proposed to simulate the chest visceral organs and soft tissue.At the same time,a finite element model is established by scanning the chest component of a physical impact dummy.(2)In order to test the validity of the dummy chest model,this paper studies the regulations of the dummy chest calibration,and builds the crash dummy calibration test.A comparison of the results of physical dummy crash test experiment and a FE simulation shows that the model has good kinematic response characteristics and the verifies rationality and validity of the model.(3)The material parameters of the model are optimized to improve its accuracy.In order to select proper chest material parameters as optimization variables,sensitivity analysis is done,a proxy model of sensitive parameters and thoracic injuries response agent model based on orthogonal test,and the parameters are optimized by genetic algorithm to obtain the optimal parameters of chest material.(4)The chest model after the material parameter optimization is verified by a vehicle collision simulation.A real frontal impact test is carried out to obtain the chest injury response curve of a physical dummy.The finite element model of the whole vehicle is built to simulate the collision test and the new chest model is used in this collision test simulation.The chest injury response of the new chest model is compared with the experimental results of the physical dummy,it shows that the design of the dummy chest is feasible and effective.Through the structural design of the crash dummy chest model,building finite element model and making analysis and optimization,the aim of the research is for searching direction of developing dummy and providing reference data for design and optimization,so this study has theoretical significance and application value to guide the engineering foundation.It is of great significance to improve the quality of vehicle safety by developing more anthropomorphic crash dummies.It is of realistic economic and social significance to accurately evaluate the safety performance of vehicles.A more reasonable improvement of vehicle safety design can contribute to the research of the protection of the passenger car in China.