2008 年 57 巻 7 号 p. 696-703
In this paper, the crashing behaviors of axial- and ring-stiffened circular tubes subjected to axial compression are studied using the finite element method. The numerical results show that the ring can lead the folding process of the circular tube to the ideal shape of wrinkles, in which case the circular tube represents the axisymmetric deformation mode. On the other hand, the effect of the axial stringer (rib) on the crashing behavior of the circular tube is to increase the compressive load by jointed parts between the cylinder and the ribs. However, the deformation falls into the unstable mode since the wavelength of folds becomes long. Therefore, in order to press down the fluctuation of the compressive load in crashing of tubes and to raise its compressive load, it is an expectable method for the energy absorption material that introduces the coupling effect of the ring and the rib.