Abstract
The double structure, in which one hollow member is installed in parallel along the axial direction with another and two members are joined by foam material, on the inside and outside of the axial direction has been shown to be lightweight, and the initial peak load value can be reduced while maintaining the energy absorption amount. At that time, if the cross section is small and the plate thickness is thin, it can be made inexpensive even by hydroforming, so as an ideal combination, the inside should have a reversed spiral origami structure of ultra-thin steel plate, and the outside should have a normal steel plate reversed twisted origami structure by a partial heating rotation molding method that can be formed at an extremely low cost regardless of the plate thickness or the size of the cross-sectional area. Among many design parameters, such as the characteristics of the foam material that joins the internal and external parts, we will try to optimize the design of the extremely difficult nonlinear problem.
