QUASI-STATIC STUDY OF THE ENERGY ABSORPTION OF ARMADILLO BIO-INSPIRED TUBES UNDER AXIAL AND OBLIQUE LOADS

Abstract

Today the implementation of biomimetic elements during the design of thin-walled structures (BTWS) is relevant among engineers and designers since bionic solutions are the result of successful evolution and adaptation processes. The current article presents the design and evaluation of five BTWS based on the nine-banded armadillo armor. The BTWS were designed considering the pectoral and pelvic patterns of the armadillo’s carapace. In all cases, the tubes were made of aluminum alloy 6061. The evaluation of the BTWS was through a numerical oblique compression test with loading angles of 0°, 5°, 10° and 15°. Oblique loading conditions are used since in practice most car crashes occur under these conditions. The numerical results revealed a decrease in the Pmax and Pm as the load angle (θ) increased. Likewise, it confirmed the superior performance of BTWS respect to conventional tube regardless of θ value. Specifically, an improvement in crash force efficiency (CFE) and energy absorption (Ea) of 86% and 78% was computed. Despite a decrease in Ea was observed as the loading angle increased, BTWS exhibited an enhancement of this parameter regard to conventional tube named HX-00. Regardless of the load angle, the best energy absorption performance was calculated for BTWS HX-04, where an average of 0.85 kJ was calculated. Lastly, comparing the bionic thin-walled structures for each loading angle, the largest crush force efficiency (CFE) of 0.74 was obtained on a structure with a main circle surrounded by smaller irregular pentagons (HX-04).