Optimum design for energy absorption of bitubal hexagonal columns with honeycomb core

This paper is concerned with the maximisation problem of the crushing energy absorption of bitubal hexagonal aluminium columns with honeycomb core under dynamic axial crushing. The honeycomb core is made up of 18 internal cell walls with the same thickness. The mass of the whole crush element and the outer dimension of the section are kept constant, while the side length of inner profile and the thickness of the inner and outer wall are used as design variables. The nonlinear explicit finite element code LS-DYNA is adopted to simulate the axial crushing behaviour of bitubal columns and the response surface method is applied to obtain the optimum design in the design space. The results show that the specific energy absorption of bitubal hexagonal columns with honeycomb core can be significantly improved by optimisation and allow us to present useful proposals for the crashworthy design of similar structures.