Research On Stiffness Of Car Body For Side Impact Based On Simplified Model

With the increased demand of vehicle for Chinese consumers, automobilemanufacturer must develop new car with shorter time and lower cost in market forkeeping its competitive advantage. Meanwhile, the occurrence rate of vehic le trafficwas increased. Particularly, in the condition of Chinese urban public traffic, theoccurrence rate and death rate of vehicle side impact accident was in high level. In theconcept phase of new car development, within the condition of lacking des ign productinformation, estimate rapidly the safety performance of new car though researchingthe side impact simplified model, exploit potentialities of concept design, and reducethe hidden design trouble. It has very important research value for projec t and canprovided guidance advise for detailed design.At first, the exchange of velocity and energy in side impact was analyzeddetailed in this paper. The mechanism of passenger injury was analyzed based on sideimpact simplified model, and the corresponding solving strategies were established.Then, the safety evaluation methodology of side impact was proposed based onvehicle crashworthiness and dummy injury. The critical technology of side impactdevelopment was introduced, such as the methods of improving accuracy of FE model,subsystem structure method and optimization design method.For illustrating the superiority of simplified model application in concept designphase, the lumped parameter model and implicit parameter model were proposed inthis paper. The lumped parameter model was composed by a series of lumped mass,nonlinear spring, and damper. The implicit parameter model which based on implicitparameter technology was composed by a series of beam, joint, and surface.The application of lumped parameter model in side impact safety developmentwas researched further in the concept design phase. Take a new type vehicledevelopment for example, a new type side impact lumped parameter model wasestablished for studying the correlation between stiffness of car body critical area andintrusive velocity and intrusion of chest, abdomen and pelvis in dummy. The accuracyof simplified model was confirmed, and the stiffness of car body critical area wasoptimized by this model.Finally, the application of implicit parameter model in side impact safetydevelopment was researched in the concept design phase. A new type side impact safety development flow based on energy management was proposed which applied inconcept design phase. Take a new type vehicle development for example, a sideimpact simplified model which car body parameterized and a side impact simplifiedmodel which trim parameterized were established separately. The accuracy ofsimplified was confirmed, and the critical design parameter was opti mized combinedwith optimization technology. The results indicated that the safety performanceassessment and lightweight design demand were solved finely by implicit parametermodel. The development period was shortened and the development cost was reduce dfurthermore.