DEFORMATION STUDIES ON THE SIGNIFICANCE OF COMBINED GEOMETRY TUBES AS ENERGY ABSORBING STRUCTURES

The deformation behaviour of cylindrical tubes have attracted the attention of researchers in recent years, due to their light weight, high energy absorption capacity and ease of fabrication. Despite their excellent crash performance, high initial peak force is a major shortcoming when they are subjected to axial impact. Though various triggering methods have been examined in the previous literature with the aim of reducing the initial peak forces, these kinds of geometrical discontinuities will decrease the stiffness of the structure and also has a drawback of reduced energy absorption capacity. Therefore, a tube configuration, which does not affect the performance of the structure in normal use, whilst it could be improving its energy absorbing characteristics and the level of deceleration pulse with delayed transfer of impact crushing force is highly desired. This article aims to propose press-formed combined geometry tubular structures which include cylindrical segment harnessed with end-caps as a frontal crash safety element in automotive vehicles.