Crashworthiness Analysis And Bending Collapse Research Of Car Bumper Beam

With the rapid growth of economy in recent years,the increasing cars ownership has brought a series of car accidents.The automotive impact safety has become the hot topic of global concern and research.As one of the main energy absorbing components,car bumpers are able to protect other vulnerable parts of automobiles from injury and reduce cost for repairing when crash accidents happen at low speed,so car bumpers must have strong comprehensive crashworthiness.Based on the car bumper system,car bumper beams with different cross sections are designed,and their crashworthiness are studied.The bending collapse mechanism of bumper beam is also studied and analyzed.The following researches in this paper have been carried out:(1)This paper presents six different sections design of the bumper beams and then uses finite element software LS-DYNA to establish the bumper-pendulum system model.Through the numerical simulation of six different car bumper beams under different conditions,the deformation and energy absorption performance of six different car bumper beams are studied.Finally the car bumper with best crashworthiness performance is obtained via COPRAS method.The results show that according to the COPRAS method,the bumper beam with a section has the best comprehensive crashworthiness and can be used for car bumper design.(2)This paper investigates the crashworthiness theoretically,numerically,experimentally under lateral load of rectangular section thin-walled tubes.The quasi-static three point bending experiment and the corresponding finite element model are first conducted to analysis the bending collapse mode.The results show that numerical results agrees well with the experimental results and the theoretical moment-rotation curve agrees well with the numerical results after the bending rotation reaches 35 degree.Specific energy absorption characteristics are compared based on the validated numerical models,which shows that the theoretical results can predicate the trend of energy absorption of tubes with different section types.Furthermore,the influence of the width to depth ratio and the slenderness the section on bending performance for the rectangular section tubes are studied.The results again demonstrate that the theoretical bending collapse mode is accurate.