Numerical Evaluation of Energy Absorption of Crashworthy Structure for Railway’s Rolling Stock: Application of Damage Mechanics Model

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.