Design of Crash Worthy Impact Attenuator for Racing Automotive Applications: Explicit Nonlinear FEM Formulation

The design of crashworthy structures is a very important issue in automotive. Structures able to absorb a great amount of energy during impact are a challenge for automotive engineers nowadays. Currently, computer simulation is an efficient and cost-effective manner of designing structures. This paper is focused on the prediction of the behavior of the impact attenuator on a vehicle used for the Annual Formula SAE competition. The impact attenuator is made of expanded aluminum sheets joined by spot welding. The behavior of the crash zone is time sensitive (inertia effects) and extreme deformations occur during a collision. The commercial software LS-DYNA is used, which incorporates robust and effective explicit non-linear algorithms, for the prediction of the time dependent behavior of the impact attenuator. The finite element simulation has taken into account geometrical (contact and large deformations) and material nonlinearities. The results show the worthiness of the crash zone and its ability to smoothly absorb great amounts of energy.