Optimized foam filling configuration in bi-tubular crush boxes; a comprehensive experimental and numerical analysis

This study focuses on introducing optimized foam filled double-walled energy absorbers. To this end, different geometries and foam densities is proposed with different foam configuration including foam inside the inner wall or between the tubes. A comprehensive experimental study has been done via construction and testing different unique structures. By extracting experimental force-displacement plots of all the structures, crashworthiness behavior of the structures is studied. Based on the decision making algorithm of COPRAS the best configuration is obtained using F max , SEA and CFE as the decision functions. Finite element model of some selected structures are developed in LS-DYNA explicit dynamic software and validated using test results. Based on the best found configuration a new set of FE models are analyzed to create a meta-model by employing Response Surface Methodology (RSM) and the thicknesses of inner and outer walls are optimized via a multi-objective optimization algorithm.