The Research On The Hafei Mini-car 40% Offset Collision Performance

Nowadays safety, energy conservation and environmental protection have become three main themes of automotive development. Safety is the most important one. Life can't come back again. Whether for people in the cab or other traffic participants, safety must be put in the first place. According to statistics, every year the number of death reaches more than 180 thousand in the whole world due to traffic accident. Death toll from head-on collision takes 71.6% in various forms of collision accidents. And head-on collision is the most common accident, and offset collision is one more common form of head-on collisions. Therefore, it is significant to research on offset collision crashworthiness.There are two evaluation methods for automotive collision. One is regulations, the other is NCAP. Crash safety regulation mainly prescribes the car crash protection capability for passengers and passersby. Early in 1986, USA promulgated and enforced FMVSS 208 American head-on crash standard-which is called USA Automotive Safety Standard. Economic Commission for Europe put ECER 94"Head-on crash passenger protection"into effect in 1998.There are two research methods for automotive safety. One is to test automotive safety through whole automotive crash. This research mainly tests if the automotive meets safety regulation requirements from different countries by automotive manufacturer. The other one is automotive analog simulation analysis based on infinite metatheory. But it costs a lot of expense and lasts long. Recent years, offset crash research grandually transforms to computer analog simulation method. Real automotive crash test will be performed once performance aim has been reached through analog simulation result.The thesis mainly researches on optimization design which will enable to meet head-on offset crash regulation's requirement. At the beginning of design,vehicle bodywork per- formance standard has been set up through testing reference and competitive cars. After getting the complete through finite metatheory.The basic idea for infinite metatheory is to divide the resolving area into a certain number of small areas called unit.Connect units with dot. In every small unti, it is assumed that structure deformation and stress is simple.The computer can calculare the deformation and stress of small area, hence deformation and stress of whole structure can be calcular. If divided unit is enough small,so de-fromation and stress of each unit will be enough simple. Therefore the result will be more close to reality.Finite metatheory is used to simulate the whole vehicle parameters, and make up optimization schemes,correct digital model and simulate again. It will result in an analysis- optimization-reanalysis-optimization process. The thsis performed three times of analog simulation and optimizationl. Final analysis results reached expected performance standard.But theoretic analysis and real vehicle crash have discrepancy. So we can't get some exact parameters.Whether real crash can pass successfully, it still needs to be tested.Real vehicle crash is the most direct and accurate method to test automotive structure. No matter how good the simulation result is, it isn't convinced more than real vehicle crash result. Real vehicle crash simulates the traffic accident scene. In the principle of protecting passengers, improve and optimize automotive structure according to real crash result. Although it costs a lot of expense and takes long for real crash test, but it is the most dependable, not substituteable, test method. Through practical test, real crash results satisfy the requirements and pass offset collsion, which proves the conformity.The deficiency of this thesis is that we can't add adummy in analog simulation analysis,so it can't simulate the real vehicle crash. Analog simulation analysis only researches on crashworthiness of BIW, and it is unable to research the harmfulness standard of passengers.