A Sadighi - MSc student, Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran
M Asgari - Associate Professor, Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran

In today’s world, safety is the most prominent feature of automobiles. Therefore, the use of thin-walled energy absorbents has become considerably important in this industry. Composite absorbents have been widely used due to the fact that they are lighter than aluminum and absorb more energy. Also, bi-tubular structures have been found to exhibit a higher capacity for absorbing energy. In this paper, a number of corrugated bi-tubular composite tubes, each consisting of a corrugated cone and a corrugated cylinder with different numbers of corrugations and radii of curvature, are studied and compared with the straight single-wall and bi-tubular peers in terms of crashworthiness parameters, as in no papers corrugated bi-tubular composite structures have been studied nor compared with a single-wall composite tube or a straight bi-tubular composite structure. The finite-element method has been analyzed using LSDYNAand validated by experimental tests, exhibiting tangible improvements in crashworthiness parameters, in comparison with single-walled structures. Furthermore, a parametric study has been done on foam-filled bi-tubular structures, resulting in a beneficial proliferation in SEA

crashworthiness, composite, bi-tubular, corrugated, thin-walled structures