Finite Element Analysis of an Energy Absorbing Crush Zone Using Expanded Metal

The design of crashworthy structures is a very important issue in automotive design. 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 costeffective manner of designing structures and the understanding of their structural behavior can be studied in depth. This paper is aimed at studying the nonlinear behavior of the crush zone of a vehicle used for

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. The crush zone is made of expanded metal sheets and solid corners joined by welding. The use of expanded metal sheets reduces considerably the weight of the structure. In addition the energy absorbing properties of the crush zone are improved due to the imperfection sensitive nature of structures made of expanded metal sheets. A finite element model is built taking into material and geometrical nonlinearities using the commercial software MSC.Marc. In the numerical analysis, the crush zone is subjected to axial compression in order to obtain the energy absorbing properties of this crush zone. A sensitivity analysis is performed on the influence of the following parameters: material properties, gauge thickness, size of the expanded metal pattern and orientation of the pattern (longitudinal or transversal). The results show the enhancement in the energy absorbed by the crush zone obtained by means of using expanded metal.