Effect of length on crashworthiness parameters and failure modes of steel and hybrid tube made by steel and GFRP under low velocity impact

Abstract

The use of tubes as energy absorption structures has been prevalent for many decades and numerous studies have been done on metal and composite tubes of varying thickness, length and section geometry. This paper extends the work to hybrid tubes and presents the results of experimental work pertaining to the collapse modes and crashworthiness characteristics of hybrid tubes that were subjected to quasi-static axial compressive loading. The hybrid specimens were featured by inner mild steel tube wrapped by a material combination of glass fibres in the form of reinforcing direct roving fabric in thermosetting polyester resin. Tubes were cut at different lengths of the same circular cross-section that encompassed both classical progressive buckling and the global bending modes of failure. Particular attention was paid to the investigate effect of tube length on crashworthiness parameters and critical length to avoid global bending during quasi-static crushing of thin-walled tubes. At first, similar work was done on steel tubes to compare results obtained by hybrid tubes with plain counterparts.