A novel method for enhancing the energy absorption characteristics of circular tubular structures under axial splitting

Abstract

The present research is an attempt to introduce a novel method for axial splitting of brazen tubes in order to eliminate the dependency of the conventional splitting mechanism on a hardened steel die and improve the energy absorption capability of the presented method. Some circular tubular samples were cut out from commercial brazen tubes and the specimens were then filled with natural rubbers with different shore hardness. For this purpose, the tubes were filled by raw rubbers and placed in an autoclave for a specific time at a controlled temperature to complete the curing process of rubbers. Some slits were created on one side of the rubber-filled tubes and the specimens were compressed during quasi-static axial compression loading between two rigid plates. Based on the experimental results, the effects of diameter and wall-thickness of the tubes, length and number of initial slits, rubber shore hardness and length of initial extra rubber on the energy absorption characteristics of the specimens are investigated. Also, experimental results of the presented splitting method are compared with those of the conventional splitting method (using conical dies for splitting of empty tubes) to find an optimized energy absorber. It was found that in comparison with the conventional splitting method, the presented technique eliminates the restrictions of using almost heavy dies which significantly decrease the overall mass of the system and moreover increases total energy absorption and keeps crush force efficiency in the range of classical splitting.