Crash-worthiness assessment of thin-walled structures with the high-strength steel sheet

The crash-worthiness of thin-walled structures has been investigated for the high-strength steel 60TRIP and 60C as well as the low-carbon steel by both experiments and numerical simulation. Crush tests have been carried out for square tubes of various heights in order to observe the crush behaviour, the reaction force and the impact energy absorption of the tube. The crush test result was compared with the numerical simulation result for evaluation of the experiment and the simulation code. A constitutive relation for simulation was obtained in terms of the conventional and modified Johnson-Cook model by interpolating experimental results from both static and dynamic tests with the tension split Hopkinson bar apparatus. The dynamic response of thin-walled structures then was simulated by an elasto-plastic explicit finite element method with the plastic predictor-elastic corrector (PPEC) scheme in stress integration in order to keep track of the stress-strain relation for the rate-dependent model accurately. Simulation results show close coincidence in the crush behaviour and the reaction force with experimental results. Simulations also demonstrate remarkable difference in the reaction force and impact energy absorption between the static model and the dynamic model.