Hybrid multi-cell thin-walled tubes for energy absorption applications: Blast shielding and crashworthiness

Nowadays, thin-walled structures are recognized for their significance in numerous technical fields particularly in automotive, aeronautics, and structural engineering. State-of-the-art studies reveal various techniques for improving energy absorptions of thin-walled structures, and each technique has its pros and cons. This paper proposes a combination of two energy absorption techniques to attain a high-level energy absorber component applicable to a wide range of blast-resistant design and crashworthiness applications. Thus, experimental and numerical investigations have been conducted to study the influence of applying internal stiffeners and staking composite layers on the behavior of aluminum (AL) thin-walled tubes. Single, double, and quadruple thin-walled metallic and hybrid tubes were tested under axial quasi-static compression test. The specimens were fabricated from unidirectional CFRP, epoxy resin and aluminum alloy T6061-T6. Various crashworthiness parameters were assessed such as the absorbed crash energy, specific energy absorption, crush force efficiency, average crushing load and peak load absorbed in order to highlight the behavior of the novel configurations. The hybrid quadrable multi-cell structure showed the highest energy absorption capabilities between the other proposed configurations. Its energy absorption improved by 116% compared to the solo hollow AL tube. In addition, nonlinear finite element analysis (FEA) using the commercial ANSYS-LSDYNA Workbench software was utilized to verify the experimental results. Numerical simulations showed very good decent agreement with the experimental results. The energy absorption of the proposed techniques has been significantly improved, with the most effective configuration (Hybrid quadruple-cell) showed 131.70% more than the control single-cell AL tube.