Optimization of fatigue life and fractography analysis of knuckle joint

Abstract Steering knuckle is an important component of a vehicle suspension system, which acts as a connection point between the wheel hub and the suspension system. Since, the forces coming from the tires are transferred to knuckle with high varying loads. The design of a knuckle becomes very critical in terms of its life with high factor of safety. At the same time, the design also should be robust with the required fatigue life, right material selection and weight optimization, without affecting the desired performance. There has been a considerable effort placed in this direction to reduce the overall weight of the knuckle system by employing high strength alloys instead of conventional materials or optimizing the geometry without altering the desired functionality and its fatigue life. This project focuses on optimization and fatigue life estimation of an optimized Knuckle using Finite Element Analysis approach and fatigue tester. This is done by studying and comparing the results of a rigid baseline model with that of an optimized model through simulation and experimentation. The optimized model is arrived based on the stresses obtained from the baseline study. The fatigue life of the optimized model is evaluated under fatigue tester and fractography analysis is carried out.