Experimental and numerical investigation of axial crushing of dissimilar thickness tailor-welded tubes

Tailor-welded blanks tensile tests in which the weld lines parallel to the axis of tension are performed and the weld metal properties are determined using a "rule of mixtures" type of calculation. Based the weld metal properties, finite element analyses of tailor-welded tubes (TWT) under axial loaded were performed to determine the effects of weld modeling techniques and thickness ratio on axial collapsed deformation. An appropriate model based on the considerations of computing efficiency and accuracy about deformation mode and energy absorption is suggested. According to the results of test and simulation, with the increasing of thickness ratio, TWTs with dissimilar thickness and similar material had demonstrated non-uniform residual stack deformed modes, and differ in many ways with the traditional thin-walled tubes, such as the curve shape of load-displacement, number of the completely squeezed folding lobes and the length of the plastic folding wave. Results indicate that TWT with optimal thickness ratio and the weld line position has better axial mechanical performance than the traditional thin-walled tube, which is very important to the crashworthiness design of tailor-welded energy absorbing structures.