Crashworthiness of an improved cake-cutting multi-cell tube under three-point bending

Increasing the number of corners has shown great potential for improving the energy absorption of thin-walled pipes. In order to further improve the bending strength and energy absorption performance of the thin-walled tubes, an improved multi-cell thin-walled tube is proposed by adding three rib plates to a straight thin-walled tube structure. A three-point bending numerical model is established to clarify the bending mechanical properties of the proposed cake-cutting multi-cell tube. The results show that at the maximum number of cakes, the deformation is more stable and the specific energy absorption is 3.5 times higher than that of a traditional circular thin-walled pipe. When the loading angle is 60°, the specific absorption energy reaches the best, which is 1.1 times that when the loading angle is 30°. When the loading angle is 60°, the peak impact force is maximum when the distance between the rib position and the center of the circle is 12 mm. At other loading angles, the maximum peak impact force is achieved at a distance of 8 mm. This work indicated the effectiveness of the cake-cutting method in improving the bending strength of the thin-walled tube, which deserves more attention in future work.