Structure Design Research Of Dummy's Chest System For Automobile Safety Impacting

The passive safety research has always been one of the important tasks when it comes to automotive industry,and it contains a significant research which focuses on damage to human body caused by car collision.Since a collision test can not rely on a real person,proper physical alternatives can be used to carry out the collision experiment which is also a very effective way to obtain the human body's injury response.For the sake of the repeatability and economic of test,a finite element dummy can be used to simulate the collision effectively.Chest injury is an important cause of death and injury and it makes up a high proportion in collision accidents.There are mainly two kinds of research models for the simulation of the dummy's chest.The first one is multi-body model,it ignores the composition of the organ structure,and treats many structures as single rigid body respectively,such as the spine,skin and ribs.All those structures connect by hinges to get the system response(speed,acceleration,displacement,contact force).The second one is the finite element model based on human anatomy.This model uses rigid materials and flexible materials to simulate the arganizations such as ribs,organ tissues and skin according to their biological characteristics,and it improves a lot in various aspects: in the details of the description,the biological model of the fidelity,the quality and quantity of the grid,the full validation and so on.This model has great economics and repeatability to analyze the chest dynamics and to get the distribution of stress and strain.The car driver collision restraint system consists of several parts : belts,seats,airbags and other components.In order to achieve the capacity of the restraint system,we need to coordinate and match the belts and airbags respectively.In this paper,a restraint system is established for the head-on collision,and the model can simulate and analyze the dynamic response of the dummy during the collision.Simultaneously,the sensitivity analysis is carried out to research the parameters of the dynamic response in dummy collision test.These parameters include the Young's modulus of the material,the short-time shear modulus of the ribs and the long-term shear modulus,the decay constant,the elastic modulus and the viscosity coefficient.After analyzing the results,the paper selects the proper material parameter which is relatively sensitive to perform simulation experiments by orthogonal test.Select the more sensitive material parameters to do orthogonal test design test,and then obtain the optimal combination of sensitivity parameters by using Particle Swarm Optimization algorithm based on Simulated Annealing(SA-PSO),so as to get the optimization program on the structure design of dummy chest.