Crushing analysis and multiobjective crashworthiness optimization of honeycomb-filled single and bitubular polygonal tubes

Honeycomb-filled tubes have recently gained attention for their enhanced energy absorption capacity. This paper firstly investigates the energy absorption characteristics of honeycomb-filled single and bitubular polygonal tubes (HSBPT) by nonlinear finite element analysis through LS-DYNA. By employing a six-level judgement method, we find that both of the honeycomb-filled single and honeycomb-filled bitubular tubes with enneagonal configuration have very excellent energy absorption characteristics among the considered cases. Next, the HSBPTs with enneagonal configuration are optimized by adopting multiobjective particle swarm optimization (MOPSO) algorithm to achieve maximum specific energy absorption (SEA) capacity and minimum peak crushing force (PCF). During the process of multiobjective optimization design (MOD), accurate metamodels of SEA and PCF of the HSBPTs with enneagonal configuration are established to reduce the computational cost of crash simulations by finite element method. Numerical experiments show that the quartic polynomial functions of SEA and PCF are the suitable metamodels for both honeycomb-filled single and bitubular enneagonal tubes.