Composite impact attenuator with shell and solid modeling

Composite have been increasingly used in cars for their advantages of lightweight, high strength, corrosion resistance and easy manufacturing. Recently, carbon fiber reinforced plastic (CFRP) gains growing popularity in numerous advanced and high performance applications for crashworthiness thanks to its superior impact resistance, respect to metals or other composite materials. Maximising impact protection of carbon fibre reinforced plastic laminated composite structures, predicting and preventing the negative effects of impact on passengers are paramount design criteria for ground vehicles. In this paper the impact modelling of a frontal impact attenuator for a specific racing car will be investigated. The current work is based on the application of an explicit nonlinear finite element code, such as LS-DYNA, and on the experimental verification of the results, by means of an appropriately instrumented drop weight test machine. The thin-walled layered structure was numerically analysed using both shell and solid elements in order to reproduce the laminate as closely as possible, taking into account also the possibility during crushing of an interlaminar failure which plays a significant role during energy absorption mechanism. The proposed models are able to predict, with a good level of accuracy, the deformation process of such impact attenuator when subjected to dynamic loading as those imposed by technical regulation.