Investigation of the effect of buckling initiator on energy absorption of thin-walled circular tubes by using of numerical simulation

Cylindrical thin-walled tubes due to construction and easy installation, high energy absorption capacity are used in the automotive industry as an impact energy absorber. However, the main weakness of cylindrical tubes is in the high initial peak load. Therefore, in this paper, to overcome this weakness, a buckling initiator is used at the top of the tube. This buckling initiator is a steel rod that is installed by stretching strips at the edge of tubes. In this study, the parameters related to the initiator, including different number of pulling strips N, pre-hit height h and inclined angle of the pulling strips θ are studied. For this purpose, quasi-static simulation was conducted to determine the maximum crushing load, specific energy absorption and crush force efficiency using the software Ls-Dyna. To verify the numerical simulation, the results were compared with experimental testing. The results show that the crashworthiness characteristics and performance of the cylindrical tubes significantly improved with buckling initiator.