Multi-Response Optimization of Grooved Circular Tubes Filled With Polyurethane Foam as Energy Absorber

The main objective of this research is to improve the design and performance of the polyurethane foam-filled thin-walled aluminum grooved circular tubes using multi-response optimization (MRO) technique. The tubes are shaped with the inner and the outer circular grooves at different positions along the axis. For this aim, several numerical simulations using ABAQUS finite element explicit code are performed to study the energy absorption of these structures. The effects of the grooves distance, tube diameter, grooves depth, foam density, and tube thickness are investigated on the crash worthiness parameters of grooved circular tubes. Finite-element analysis is performed along the lines defined by design of experiments (DOE) technique at different combinations of the design parameters. The MRO is carried out using the mathematical models obtained from response surface methodology (RSM) for two crashworthiness parameters termed as the specific energy absorption (SEA) and the crushing force efficiency (CFE). Finally, by analyzing all the design criteria including the absorbed energy of tube, the mass of tube, the mean crushing load, and the maximum crushing load, the optimal density of polyurethane foam and geometric parameters were obtained through both multi-objective optimization process and Pareto diagram. A comparison of the obtained results indicates the significance of grooves distance and the inner diameter of the tube as the most influential parameters