Crashworthiness analysis of octagonal-inner double tube with different thickness under offaxis oblique load

Abstract

The crash tube is one of the important parts to reduce the effects of accidents. The design of crash tube only watches the frontal crash, but oblique crash might affect the passengers. Besides, Lack of oblique-loading researches in crashworthiness becomes causes to analyze crash tubes more. This paper aims to study crashworthiness performance of octagonal-inner double tubes under off-axis oblique impact load (0°, 10°, 20°, and 30°). The tubes have been connected with two walls, top wall as moving wall and a bottom wall as rigid wall underl different load angles. The tubes were made from Aluminum Alloy and consisted of a circular-outer tube and an octagonal-inner tube. The crashworthiness parameters of absorption of specific energy (SEA), maximum collapse force (Fmax) and efficiency of crush force (CFE) were obtained for all the structures. In order to get the value of parameters, the method of finite element analysis was used. The effects of different thickness of 1 mm, 2 mm, 3 mm and 4 mm and various oblique were studied. Based on numerical results, structures of 4 mm thickness were the greatest SEA of 26.39 kJ/kg among other thickness of structures. In addition, the value of energy absorption for tubes obliquely loaded decreased for all the size of thickness structures. Finally, this structure can be considered as crash box of vehicle in future.