Study on new crashworthy buffers in railway

At the collision time, a lot of energy is generated during a short period of time that causes large deformations in bodies. One of the most important parts of wagon in railway is a buffer which may absorb the energy during an impact. It should be mentioned that normal buffers only absorb the energy resulted from a crash elastically. In the present paper, it is tried to use inversion mode of deformation in cylindrical tube, in order to improve energy absorption of new design buffers through plastic deformation, in addition to elastic energy absorption. On the other hand during sever impact the improved buffers may enter plastic phase and absorbs some of the energy generated by impact in this phase after being deformed elastically. The main structure of buffers is composed of cylindrical tubes which can prevent deformation of important structures such as wagons through being deformed at the impact time. One of the most stable and practical modes of energy absorption for cylindrical tube in plastic state is inversion. In this paper, inversion is used to increase the amount of energy absorption in railway buffers. In addition, the features of force–displacement curves, energy–displacement curves, and deformation modes are analyzed by using the non-linear finite element code LS-DYNA.