Failure analysis of a train coach underframe

•A railway component failure analysis has been performed based on material characterization methods and numerical simulations.•A methodology used to identify the energy absorbed in a railway impact is proposed.•A FEM is generated based on material information and deformations of elements involved in a real railway collision.•The behavior of an energy absorber device in the event of a collision is analyzed.•The results obtained are the force and energy in a railway impact. Energy absorbing devices are components installed in vehicles that partially transform the impact energy in deformation, improving system crashworthiness and dissipating forces that occupants would be exposed to in the case of collision. These components are designed in such a way that in the case of an event of this type, the energy is absorbed by yielding, avoiding damage to passengers, to cargo and structure of the train. In this paper the failure analysis of the underframe crumple zone in a train car, consequence of the railroad collision with a different vehicle is exposed. The study has been performed by finite element simulations of the component object of study, taking into account geometric and material non-linearities. The geometry introduced in the finite element model was measured in both deformed and in non-affected devices, and the mechanical properties of the structural components have been obtained by means of tests carried out for their evaluation. The impact force transmitted to the energy-absorbing component (423 kN) has been calculated by analizing the deformation suffered by the energy absorbing device on the impact. The energy absorbed in the device is estimated in 79.01 kJ. The main conclusion of this work is that the component acted properly after the impact, which protected the passengers from serious consequences.