Abstract
Automobiles are indispensable means of transportation for daily life, and ensuring the safety of occupant passengers is an important issue. Therefore, researches for improving the impact energy absorption characteristics of automobile crash boxes are actively conducted. In this research, in order to develop a shock absorbing member with higher energy absorption characteristics, the purpose is to predict the shock absorbed energy in a double circular tube filled with water inside. FEM analysis of water filled double circle tubes subjected to axial impact was carried out. In addition, a theoretical model for determining the axial average load was constructed, and the energy absorption was calculated using the theoretical equations for the empty tube and the value when 60% of the total length of the model was compressed. Theoretical estimations of the amount of energy absorption are carried out by these products and compared with the result of FEM analysis. It is found that the average axial load is accurately matched in the FEM analysis and theoretical predictions and the energy absorption can be obtained by setting the energy absorption range to the theoretical equations for the empty tube or 60% of the total length ofthe model. It enables us to estimate impact absorption energy in a double circular tube filled with water inside.
