Optimisation of collapse in functionally graded thickness honeycomb under axial impact loading

Abstract

This research investigates the collapse behaviour of a honeycomb energy absorber featuring variable wall thickness. Initially, numerical simulations were conducted to analyse the effect of wall thickness in upper and lower sections of the absorber, as well as the parameter 'n‘ that characterises the type of thickness variations within the wall, as design variables. A comprehensive database was compiled, encompassing various combinations of these parameters. Subsequently, a mathematical model was developed by fitting it to the initial data using the response surface methodology. The specific absorption energy and initial crush force were computed and utilised as the objective function for optimisation. Ultimately, by employing the Particle Swarm Optimisation (PSO) technique and applying problem constraints, an optimal configuration for the honeycomb absorber was determined, with a focus on maximising the specific absorption energy. The optimised outcome obtained from the optimisation algorithm exhibited an enhancement of approximately 11% compared to the maximum values of the input samples. Furthermore, multi-objective functions were employed during the optimisation process to identify absorber parameters that would achieve both the maximum specific absorption energy and the minimum initial peak force.