Simulation And Research Of The Structure Of Crash Box In The Low Speed Front Collision

With the trends for higher speed and lower weight of automobile design and the increasing number of vehicles, how to improve the passive safety and reduce the cost of repairing has become important tasks for automobile makers.The research method of crash performance has always been the combination of tests and computer simulatons.According to crash box frontal crash test in low speed,the crash box model is built with shell elements in Hypermesh. The CAE model is simulated with the software of LS-DYNA.Comparing to test and theory data,the model is proved feasible.Key factors for crashworthiness of crash box are pointed out, and some results have been obtained.Firstly the basic mechanical equation used in the simulation of the box crash, the finite element discretization of the box structure, the explicit integral algorithm are introduced. In order to improve the simulation precision and efficiency, the foundation of the finite element model of the crash box, the control of the element discretization and the gridding density, the definition of the contact interface, the hourglass control, the mass scaling and the subcycling etc. are discussed, the effect of the parameters on the simulation precision and efficiency are found . Afterwards, the crash process of the thin-walled structure is simulated to find the effect of the cross section and the pre-deformation on the crash capacity.The numerical simulation methods,content and result of this paper have some reference values of technology for the design of the crash box.From the point of setting up the parametric model between other structures and the characteristic of the deformation and energy absorbing of the crash box,this paper is a basic start of studying the connection between the repair cost of damaged vehicles and the characteristic of the deformation and energy absorbing of the full vehicle.The research and analysis of this paper have important meaning in further studying the characteristic of the deformation of full vehicle and reducing the cost of repairing. It is also important for the vehicle's lightweight design.The conclusion of this paper is referenced to other vehicle crash simulation. It's also good for vehicle body design.