Crashworthiness of double-cell conical tubes with different cross sections subjected to dynamic axial and oblique loads

Thin-walled tubes are increasingly used in automobile industries to improve structural safety. The present work deals with the collapse behavior of double-cell conical tubes subjected to dynamic axial and oblique loads. Crashworthiness of these tubes having different sections (e.g., circular, square, hexagonal, octagonal, decagonal) was numerically investigated by using an experimentally validated finite element model generated in LS-DYNA. Geometry of these tubes was then optimized by decreasing the cross section dimensions at the distal end while the weight remained unchanged. Octagonal conical tube was finally found to be more preferable to the others as a collision energy absorber. In addition, square and circular tubes showed diamond deformation mode, while the other tubes collapsed in concertina mode. A decision making method called TOPSIS was finally implemented on the numerical results to select the most efficient energy absorber.