Multiobjective Optimization of Functionally Corrugated Tubes for Improved Crashworthiness under Axial Impact

Abstract

This study aims to analyze the effectiveness of introducing sinusoidal corrugations with varying wavelength and amplitude along the length of cylindrical tubes in order to improve their energy absorption characteristics. Different sinusoidal functions are used to obtain the generatrix of corrugated profiles. Non-linear finite element code LS-DYNA is used in order to carry out the numerical analyses of these corrugated tubes under axial loading conditions. The results obtained from the analyses are then used to obtain functions using MATLAB's native non-linear regression tool fitnlm. Two objectives are to maximize the Energy Absorbed (EA) by the tube and to minimize the Peak Crushing Force (PCF). The degrees of graded corrugation functions (Amplitude and Wavelength function) are chosen as the two design variables in this study. Unconstrained multiobjective Genetic Algorithm is the optimization algorithm used in this study using MATLAB to produce the Pareto frontier which gives an optimal set of tube configurations.