Approach to impact analysis of automobile Al alloy wheel in presence of casting shrinkage defect

Abstract

The objective of the research was to evaluate the effect of casting shrinkage defects on the impact properties of cast aluminium alloy wheel for automobile. Most structure design engineers give the casting parts an overestimated factor of safety, specify extensive quality tests and perform extensive performance testing due to worries about unavoidable defects, such as shrinkages; however, all of these methods do not necessarily guarantee performance, and they are all somewhat costly. In this paper, an approach using computational impact analysis for an Al alloy, where shrinkage defect exists, was proposed to solve the motioned problem. The shrinkage defects were modelled by the shape simplification method. The method reconstructs the shrinkage defects to hollow spheroid primitive based on the shrinkage shape data obtained from industrial computerised tomography. The results of the simulation of wheel with shrinkage defect were compared with the results of ignoring shrinkage. Comparative results showed that when the impact analysis was applied to an Al alloy wheel, a traditional analysis without considering the shrinkage defect estimated the wheel safety; however, the results considering shrinkage defect show that the wheel would fracture under the same test condition.