Strength Analysis and Fatigue Life Prediction on Steering Knuckle

In the process of operation, the loading condition of automobile steering knuckle is very complex, which seriously affects its structure strength and fatigue life. In this paper, finite element analysis is applied to calculate and analyze the deformation and stress distribution in steering knuckle under conditions of three kinds of limit load, which are impulse force induced by rough ground, longitudinal impact caused by emergency braking, transverse impact generated when the car turned. Based on this, a prediction of the fatigue life on the more than 300000 times of cyclic loading is also carried out. The results show that under the three kinds of limit load conditions, the maximum stress value of the steering knuckle of 940 MPa, which is less than the yield strength of steering knuckle materials, so the steering knuckle won't produce yield. Fatigue strength analysis shows that the fatigue life application factor is 0.9375, less than 1, which illustrates that fatigue damage will not occur. The study provides an important theoretical basis and technical support for the actual design and industrial production of automobile steering knuckle.