Crashworthiness analysis of thin-walled bio-inspired multi-cell corrugated tubes under quasi-static axial loading

Abstract

This paper proposes a bio-inspired multi-cell corrugated tube for use in energy absorption. The proposed structure consists of two parts: an inner rib and a corrugated tube into which the inner rib is inserted. The structure of the corrugated tube is specified using a cosine expression based on two parameters, that is, the number of cosine wave crests and their amplitude. Two inner ribs with different sections (X-shaped and Y-shaped) were designed and the crashworthiness of the resulting tubes was analyzed. The crashworthiness was determined using the finite-element program LS-DYNA. The numerical results show that the modes of collapse of the multi-cell corrugated tubes can be classified into four types: unstable, diamond, ring, and mixed modes. Each mode is strongly affected by the number of cosine wave crests and their amplitude. By analyzing the force–displacement performance and crashworthiness indicators, it was found that tubes with appropriate number of wave crests and amplitudes, and inner rib shape experience lower initial peak forces and increase energy absorption and specific energy absorption (compared with a traditional straight tube with the same inner rib). The undulation in the load-carrying capacity is also decreased. Thus, the multi-cell corrugated tubes have good crashworthiness.