Comparison of Energy Absorption Characteristics of the Plain Fold and Spot-Welded Fold Tubes Under Three-Point Bending

Abstract

Thin-walled square tubes are used as automotive vehicular crash structures since they can be easily constrained at the endpoints. These tubes are generally produced by costly extrusion process and special mold designs are required for making the same. This research work proposes a novel idea of making by folding thin metal sheets into square tubes that can be easily prepared, cost-effective and flexible in sectional shape. However, spot welding can be used to enhance the bending resistance and energy absorption. Bending collapse of tubes is one of the most important deformation mechanisms to be ascertained to ensure the safety of people or cargo under accidental crash events. Three-point bending tests are generally employed to investigate the bending characteristics and hence performed on plain folded and spot-welded fold tubes. Results revealed that spot-weld and number of turns have an important influence on the bending resistance of the folded tubes. The comparison between traditional tubes and welded tubes showed that the welded tubes outperform the traditional tubes in some aspects like minimizing the peak force and maximizing energy absorption. Adopting a number of turns further increased the bending resistance of the tubes compared with traditional square tubes.