The energy absorption of a crashworthy structure for railway’s rolling stock was studied experimentally and numerically. A quasi-static compression test was conducted using a full-scale mockup of a crashworthy structure constructed with welded aluminum alloys. To predict the experimental results, a finite element (FE) simulation was conducted in which the Gurson-Tvergaard-Needleman (GTN) model, representing the accumulation of ductile fractures by the nucleation, growth and coalescence of micro-voids, was employed as the constitutive equations of the parent aluminum alloys and welded regions. A simulation employing the Von-Mises yielding model as the constitutive equations was performed as a conventional approach to demonstrate the advantages of the simulation using the GTN model in predicting the energy absorbing ability. The predictions of the GTN model simulation were proved to be in better agreement with the experimental data than those of the simulation based on the Von-Mises model. The relationship between the total energy absorption and the local phenomena observed in the compression test is discussed.

No 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 accurately reproduced in the FE simulation employing the damage-mechanics model, while the buckling behaviors were predicted with substantial accuracy in both simulations. Comparison of the experimental results and the numerical predictions also revealed that the FE simulation applying the damage-mechanics model had an advantage in accurately predicting the energy absorption. The relationship between the local phenomena and the structural energy absorption is discussed.

No abstract

No abstract