セル構造を有する衝撃吸収部材のエネルギー吸収特性の検討

抄録

In automobiles, an impact absorbing member called a crash box is provided to absorb impact in the traffic accident. The impact energy is absorbed by deforming the crash box when a collision accident occurs, and the safety of the occupant is protected. However, in the conventional crash box such as a rectangular-shaped tube type and a hat-shaped type, there is a problem that the load in the initial stage of collision increases rapidly. In order to solve this problem, we focused on the energy absorption characteristics of the cell structure such as the wood structure with multiple large and small holes. To propose the crash box with the cell structure, we studied the effects of the arrangement of holes and size of holes in the cell structure on crash behavior using finite element analysis software LS-DYNA^®. First, three types of models with different arrangement of holes were analyzed. From the analysis results, it was found that stress concentrates on cell walls between holes in all models. Next, from the above results, we analyzed models in which the thickness of cell walls and the ratio of the diameter of large holes and that of small holes were changed variously. As a result, it was found that the load-displacement curves have the same shape if the ratio is the same in spite of the wall thickness of the cell.