Failure analysis of a re-design knuckle using topology optimization

Abstract

In this study, a systematic design process is carried out for the design of the knuckle. A systematic method is proposed for the design and analysis of a lightweight steering knuckle in an electric vehicle. In the proposed approach, a finite element (FE) model of the knuckle is constructed based on an inspection of the suspension and steering requirements of the target vehicle and the results of a kinematic analysis. A two-stage topology optimization method is then applied to refine the material distribution within the FE model in such a way as to minimize the knuckle weight. Finally, FE simulations are performed to evaluate the strength of the knuckle under road impact conditions and to determine the fatigue life of the knuckle for four ISO 8608 road classes (A–D). The results show that the optimized knuckle has a weight of 3.64 kg (approximately 6.2 % lighter than the original knuckle of the same strength and material) and achieves fatigue lives of 2.512×1011, 2.972×108, 5.598×103 and 2.432×101 cycles for road classes A, B, C and D, respectively.