Finite Element Dynamic Analysis of a Railway Seat Under Longitudinal Impact Condition

For a railway vehicle, the structural integrity of the seat frame and of its connection to that of the coach is a very important aspect of the design phase addressed to the improvement of the passive safety performances, at most because the analysis of the accidents occurred in recent years shows that secondary impacts against vehicle interiors remain one of the main causes of injury. All regulations which apply to this task start from the assumption that whatever happens to the vehicle the seat must remain connected to the vehicle frame, as well as the different parts to each other. Numerical evaluations are obviously necessary to match with this design requirement; it would be desirable to apply multi-body (MB) codes to this task, as they are really fast, but unfortunately they can’t provide detailed results for what concerns the structural behaviour of the involved seat and vehicle components. For this reason, in the present work a full finite element model of a sled-test, including a FE dummy, has been developed, analysed and validated by comparison with the available experimental results; it has been also showed how this kind of numerical simulation is suited and necessary to evaluate the structural behaviour of the structural components of the seat frame. In the context of the presented study the MADYMO® code has been adopted to perform the preliminary MB analyses necessary to calibrate and evaluate the relevant parameters of dummy-seat contact surfaces and of seat-belt stiffness, while LS DYNA® code has been used for the structural dynamic FE analyses.