Investigation of the numerical, experimental, statistical and optimization of thin-walled energy absorber with novel configuration using response surface method under axial loading

In this study, aluminum thin-walled cylindrical absorbers for crashworthiness are investigated to introduce a novel system with better energy absorption and crushing characteristics under quasi-static axial compressive loading. The inside of the thin-walled cylinders is meshed with a square welded from vertices to the thin-walled cylinder. Here, the response surface method, which is one of the design of experiments techniques has been used to examine the effect of the parameters on energy absorption, initial peak crushing force, specific energy absorption per unit mass and energy absorption per length. The variables of thickness (t), height (h) and length of square (l) of the thin-walled cylinder were considered in three levels and initial peak crushing force, specific energy absorption per unit mass and energy absorption per length were selected as response. The specimens were analyzed under a quasi-static compressive test at a constant speed of 10 mm/min. Subsequently, for further investigation, the experimental results were compared with those obtained from the finite element simulation using Abaqus software, which indicated desirable accuracy. To decrease the solution time in this numerical analysis, the speed was set at 0.5 m/s. Finally, the experimental results were compared with the simulation ones, which showed acceptable compatibility. Further, there are the equations obtained from the multi-objective optimization testing design. The results indicated a linear relationship of thickness with responses, nonlinear relationship of height with responses, linear relationship of length of square with initial peak crushing force, and nonlinear relationship with specific energy absorption per unit mass and energy absorption per length.