Expansion tubes as impact energy absorbers: Experimental investigations and numerical simulations

Railway vehicles require energy absorbers which dissipate energy at a constant load, resist transverse loading and which are compact. The expansion tube energy absorber is a kind of energy absorption device. The expansion tubes achieve the energy dissipation by means of plastic deformation and friction. The structural parameters of the expansion tube absorber is proposed by the authors to provide improved energy absorption properties over existing devices. This paper contributes to the analysis and investigation of the crushing characteristics of the expansion tube energy absorber using the ANSYS/LS-DYNA finite element code. Corresponding tests were conducted to serve as comparison purpose. Satisfactory level of agreement between simulation and testing results was obtained regarding the main characteristics of the tested expansion tubes such as energy absorption and the crushing force. The numerical simulation accurately predicted the performance of the expansion tubes under quasi-static conditions. Which proves the simulations can direct the design of expansion tubes as impact energy absorbers, and an optimized design idea is put forward to improve the energy absorption efficiency.