Analysis of the Collapse Behaviour Regarding TWB Crash-Boxes in Conjunction with the Construction Technique

The crash-boxes are thin-walled structural components with rectangular cross-section which are utilized in the construction of the resistance body structures in the auto industry. This components can be manufactured from various materials including homogenous steel sheet metals, tailor welded blanks (TWB) or even composite materials. The benefits of using TWB were shown in numerous studies before and they are not the main purpose here.This research focuses on the collapse behaviour of TWB thin-walled structures with rectangular cross-section subject of impact loadings. The main objective is to design a crash-box which allows the absorption and dissipation of great kinetic energy constituting better resistance structures for car bodies.After analysing the resulted data, a few aspects regarding the TWB crash-boxes were revealed and some conclusions could be suggested: the weld line generates a barrier like zone which delays in some manner the propagation of the progressive buckling levelling the mean crash load; no flange crash-boxes presented best results regarding the mean crash load even if the data were very close to the other crash-box types. Furthermore, the peak crash load was at maximum level comparing with the other crash-box types. This collapsing behaviour of the no flange crash-boxes could be assigned to the fact that the bonded sides of the structure work like double walls into the same cress-section and is not really affecting the asymmetric crash mode of the structure.