Evaluation of Energy Absorption of Crashworthy Structure for Railway's Rolling Stock (Numerical Simulation Using Damage-Mechanics Model)

Abstract

The energy absorbing ability of a crashworthy structure for a railway's rolling stock composed of welded aluminum alloys was evaluated numerically using finite element analysis (FEA). In the numerical simulation, two different material models were employed to characterize the base aluminum alloys and welding materials: one was a damage-mechanics model and the other a conventional plastic-mechanics model. The energy absorbing abilities of two different types of crashworthy structures were predicted using the FE simulations, and the numerical predictions were compared with experimental results obtained from quasi-static compression tests using mockups of these two crashworthy structures. The local phenomena, buckling and fractures, observed in the mockup tests, were also predicted numerically. The local fractures were found to be accurately reproduced in the FE simulation employing the damage-mechanics model, while the buckling behaviors were predicted with substantial accuracies in both of the two simulations. Comparison of the experimental results and the numerical predictions also showed that the FE simulation applying the damage-mechanics model had an advantage on accurately predicting the energy absorption. The relationship between the local phenomena and the structural energy absorption is discussed.