Numerical modeling of energy absorption characteristics in straight and twisted thin-walled tubes under axial loading

In this study, the axial crushing and energy absorption characteristics of straight and twisted thin-walled tubes with polygonal cross-sections were investigated. The effect of geometric twisting on deformation stability, mean crushing force, crushing force efficiency, and specific energy absorption were analyzed by means of finite element simulations. The tubes, modeled with mild steel material, were subjected to dynamic axial loading to capture progressive folding and local buckling mechanisms. The presented numerical model was justified with research in literature, confirming agreement in absorbed energy and mean crushing force, hence demonstrating the reliability of the developed model. The results revealed that a moderate introduction of twist enhances folding uniformity, reduces global buckling and force oscillations, hence improving overall crashworthiness. Hexagonal and octagonal sections exhibited improved folding uniformity and energy absorption efficiency compared to square tubes among the geometries studied in this work. The findings emphasize the significance of a proper twist angle can serve as an effective design parameter to balance deformation stability and folding, energy absorption, and maximum load reduction in lightweight crashworthy thin-walled structures.