Dynamic axial crashing of tailor-welded blanks (TWBs) thin-walled structures with top-hat shaped section

In this paper, dynamic axial crashing analysis of tailor-welded blanks (TWBs) thin-walled structures with top-hat shaped section under front impact is presented. The crash tests are performed through a sled test in order to model a car-to-car front impact. The strain rate dependence of both high strength steels (DP590 and DP780) is considered to study its influence on acceleration and energy absorption involved into high speed impacting process. The FE model about the front dynamic crashing is conducted, and different weld line modeling types on the dynamic simulation results such as acceleration history are compared. It demonstrates that coincide node (CN) model is considered appropriate for simulating the dynamic impacting. Additionally, the effects of weld line locations and spotweld spacing are also performed. It may be concluded that the material and thickness properties of front end have certain influence on the crashworthiness performance of TWBs. The simulation results show that the acceleration curves of three TWB combinations are insensitive to spotweld spacing. A comprehensive analysis including the crash mode, the acceleration curves and the energy absorption is carried out for crashworthiness assessment. The obtained results can provide some insightful guide information and fundamental supports for light-weight and crashworthiness design of TWBs to a certain extent.