Partially curved-wall polygonal tube with multi-phase plateau force under quasi-static loads

The plateau force is an important factor affecting the performance of energy absorber. In this paper, a partially curved-wall polygonal tube (PCPT) is proposed by studying the relationship between the section shape and the force–displacement response of hexagonal and circular tubes. According to the different contact modes in the deformation process, PCPT can be divided into curved wall phase and straight wall phase. The stiffness, plateau force and the transition position of the curved wall phases can be regulated by the ovality h and the straight wall angle β. The multi-straight wall design makes the straight wall phase of PCPT have stepped plateau force, which improves the energy absorption. The desired plateau force characteristics can be obtained through parameter adjustment, such as stable plateau force. As an energy absorber, PCPT has excellent designability.