Carbon fibre composites have shown to be able to perform extremely well in the case of a crash and are\ud being used to manufacture dedicated energy-absorbing components, both in the motor sport world and\ud in constructions of aerospace engineering. While in metallic structures the energy absorption is achieved\ud by plastic deformation, in composite ones it relies on the material diffuse fracture. The design of composite\ud parts should provide stable, regular and controlled dissipation of kinetic energy in order to keep the\ud deceleration level as least as possible. That is possible only after detailed analytical, experimental and\ud numerical analysis of the structural crashworthiness.\ud This paper is presenting the steps to follow in order to design specific lightweight impact attenuators.\ud Only after having characterised the composite material to use, it is possible to model and realise simple\ud CFRP tubular structures through mathematical formulation and explicit FE code LS-DYNA. Also, experimental\ud dynamic tests are performed by use of a drop weight test machine.\ud Achieving a good agreement of the results in previously mentioned analyses, follows to the design of\ud impact attenuator with a more complex geometry, as a composite nose cone of the Formula SAE racing\ud car. In particular, the quasi-static test is performed and reported together with numerical simulation of\ud dynamic stroke. In order to initialize the collapse in a stable way, the design of the composite impact\ud attenuator has been completed with a trigger which is consisted of a very simple smoothing (progressive\ud reduction) of the wall thickness. Initial requirements were set in accordance with the 2008 Formula SAE\ud rules and they were satisfied with the final configuration both in experimental and numerical crash\ud analysis

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Composites are materials of choice for lightweight structures due to their excellent strength/weight/and stiffness/weight/properties. For several years, the application of composite materials with continuous fiber was limited to those with thermosetting matrix. Recently, interest in composites with thermoplastic matrix is growing thanks to their considerable advantages also in terms of recyclability. The thermoplastic composites appear to be the right alternative to the materials currently used, replacing not only the non-structural parts, but also the structural components located in areas potentially subject to impacts.\ud This paper presents the results of an experimental campaign made on a fully thermoplastic composite, where both the reinforcement and the matrix are made in polypropylene. The target is to analyze its behavior under different impact loading conditions using a drop weight testing machine. The influence of the impact mass and of the velocity on the energy absorption capability of the material have been analyzed and discussed. During the tests, the material showed a ductile behavior and developed extended plasticity without a crack tip. The main observed damage mechanisms were the yarn sliding

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