Experiment and simulation for the crushing of tailor rolled tubes with various geometric parameters

Abstract By properly controlling the parameters of the rolling mill, multiple types of tailor rolled blanks (TRBs) are obtained, which in turn are used to form the tailor rolled tubes (TRTs) with axially varied thickness. Axial-crushing tests have been performed, and the results show that the reaction forces of TRTs show a rising trend with the integrative effect of crushing and repetitive load fluctuations after reaching the relatively low initial loads. Furthermore, investigations of different thickness and lengths are introduced into the TRT structures. It can be concluded that more energy can be absorbed for TRTs when choosing more edge numbers of the polygonal cross-sections. By contrast, the biggest difference in energy absorption is between the triangle and circular section shape, which is about 43.4%. In addition, the energy absorption capacities of TRTs with longer tube or side lengths are improved, but the energy absorption efficiencies are decreased by 21.76% and 8.7%, respectively. Meanwhile, the various distributions of transition zone and layout mode not only alter the characteristics of load curves but also affect the energy absorption capacity and initial resistance. Furthermore, multi-tube structures including TRTs, tailor welded tubes (TWTs) and traditional uniform tubes (UTs) are introduced to carry out the contrast crushing experiments. The initial peak loads of TRTs are the lowest, which are in the range of 43.05–58.28 kN. For the energy absorption, the UT structures can absorb more energy before the moving head reaches about 2/3 of the overall collapse stroke. However, the ability of TRTs to absorb energy is improved significantly in the later stage, making the overall energy absorption greater than in UTs. The reasons for the improved energy absorption efficiency of TRTs are discussed in detail. The corresponding FE models considering the variation of thickness and material properties of TRTs are established and verified with the experiment results. In order to conveniently predict the energy absorption performance of crushing TRTs, mathematical models are adopted.