Experimental Study Of Thickness Graded Thin-Walled Tubes As Vehicle Front Rail Under Oblique Loads

With the continuous development of the automotive industry, the automobile makes our manufacturing more convenient and efficiency. But at the same time, along with the popularity of the automobile, road traffic accidents have become unavoidable, which cause more and more people pay attention to the automotive passive safety. Among them, crashworthiness analysis of automotive components has become a key point in the automotive passive safety. The vehicle crashworthiness mainly means that during a car crash, the vehicle body via shrinkage deformation to absorb the external impacts energy and protects the members inside the car. During the collision, the front longitudinal beams are the main component to absorb the crashing energy. A large number of experimental researches show that the crash and failure modes of thin-walled tube (TWT) are very similar to the front rail. Therefore, in the crashworthiness analysis, thin-walled tube can be used as a simplified model of front rail.In this paper, the experimental research carried out on own-designed and manufactured testing device for TWT under oblique loads. The specific energy absorption (SEA) and the mean crushing force are adopted as performance indices to investigate the failure modes and crashworthiness of a novel thickness graded thin-walled tube for vehicle front rail under oblique impact, the variable parameter includes tube’s length, thickness and angel. It is found that the functionally thickness graded thin-walled tube effectively increases the tube’s critical angle under oblique loads, and its crashworthiness is superior to uniform thin-walled tube. This paper provides guidance for the crashworthiness analysis and design of vehicle front rail under oblique loads.