ENERGY ABSORPTION CAPABILITIES OF THIN-WALLED MULTI-CELL CORRUGATED TAPERED TUBES UNDER AXIAL AND OBLIQUE IMPACT LOADING CONDITIONS

Abstract

Progressive collapse behavior, high energy absorption, low manufacturing cost, and lightweight made the thin-walled structures a great safety device in the automotive industry for crash energy absorption. In this thesis, a numerical analysis is conducted to investigate the multi-cell corrugated tapered tubes (MCTTs) as thin-walled energy absorbers under axial and oblique loading conditions. The analysis highlights the effect of the geometric factors and impact angles on the MCTT performance indicators, which are energy absorption (EA), specific energy absorption (SEA), mean force (MF), and initial peak force (IPF). An explicit numerical finite element model is created and validated against experimental work. The developed MCTT is made of AA6060 Aluminium alloy and has been crushed with a 275kg striker moving at a velocity of 15m/s with five different impact angles. The results showed that adding plates to the corrugated taper tubes improved EA and SEA. It is found that the most influencing factors on the EA and SEA are the number of plates and plate thickness; having more and thicker plates worked on increases the IPF and MF, and as a result, it increases the EA and SEA. Higher corrugation amplitude reduces the IPF and MF, resulting in a drop in the MCTT's ability to absorb energy (EA and SEA). The ability of the MCTT to absorb energy (EA and SEA) is reduced as the impact angle increases, whereas the IPF and MF are also reduced. The corrugation amplitude played the main role in the obtained deformation modes. The MCTTs collapsed in axisymmetric and mixed deformation modes under axial and low impact angles, and above 10˚, a buckling deformation mode is developed.