Searching the energy absorption capability of composite impact attenuators with the particle swarm optimization

In the last decades the replacement of conventional materials with innovative composite ones is increased significantly thanks to their advantages of lightweight and high specific strength. Nevertheless the heterogeneity and the various damage mechanisms of composite materials make their modelling very difficult. Very few attempts have been done from the analytical point of view in order to describe and predict the impact behavior of composite impact attenuators under axial loading. Towards this goal optimization techniques play an important role as a useful decision making tool in the design of structures. In the present study a theoretical analysis of the failure mechanism, pertaining to the stable mode of collapse, of thin-walled tubes with circular section subjected to axial loading is exposed in order to predict the mean loads and the crush lengths during collapse. The analysis is based on an energetic approach aimed at finding the minimum of the average load function, dependent on several variables, which represents the best configuration of crushing. This was obtained using the particle swarm optimization algorithm. Such type of approach can be useful to design simple structures, as impact attenuators, under axial loading, obtaining results in a short time.