A comparative study on the windowed and multi-cell square tubes under axial and oblique loading

The collapse of thin-walled tubes under axial and oblique loading is frequently encountered in real crash events. The windowing and multi-cell methods are effective in improving tubes' energy absorbing performance. In this paper, a comparative study on the performance of windowed and multi-cell square tubes of the same weight under axial and oblique loading is conducted numerically. The results show that the multi-cell tube can achieve higher mean crushing force than the windowed tube but the windowed tube has lower initial peak force. The effectiveness of both methods reduces as the load angle increases. Moreover, the multi-cell and windowed tubes may have worse performance than the conventional tube if the former two collapse in global bending and the later in axial mode.

► Windowed and multi-cell square tubes under axial and oblique loading are numerically simulated.
► Under axial loading, the windowed and the multi-cell tubes have better performance than the conventional tube.
► Under axial loading, the windowed tube has lower initial peak force and lower mean crushing than the multi-cell tube.
► At small load angles, the windowed and the multi-cell tubes may perform worse than the conventional tube.
► At large load angles, the windowed tube has lower initial peak force than the conventional tube.