Crush analysis and multi-objective optimization design for circular tube under quasi-static lateral loading

• Laterally crushed circular tubes were studied as energy absorption structures.
• The crush behaviour was identified through finite element and response surface methods.
• Desirability approach was employed to find the optimal design of the circular tube.

This paper addresses the energy absorption behaviour and crashworthiness optimisation of short length circular tubes under quasi-static lateral loading. Finite element (FE) models were developed using implicit FE code ANSYS to simulate the deformation behaviour and energy absorption of circular tube under lateral loading. These FE models were validated using experimental techniques to ensure that they can predict the responses of circular tube with sufficient accuracy. Response surface methodology (RSM) for design of experiments (DOE) was used in conjunction with finite element modelling to evaluate systematically the effects of geometrical parameters on the energy absorption responses of laterally crushed circular tubes. Statistical software package, design-expert, was used to apply the response surface methodology (RSM). The energy absorbing responses (specific energy absorbing capacity (SEA) and collapse load (F)) were modelled as functions of geometrical factors (tube diameter, tube thickness, and tube width). These developed functions allow predictions of the energy absorption response of laterally crushed tubes, based on their geometry parameters. Based on DOE results, parametric studies were conducted to generate design information on using the laterally crushed tubes in energy absorbing systems. Finally, the approach of multi-objective optimization design (MOD) was employed to find the optimal configuration of the proposed energy absorption structures. Design-expert software, which employs the desirability approach as optimization algorithm, was used for solving the MOD problem.