On the Need of Kurtosis-Based Technique to Evaluate the Fatigue Life of a Coil Spring

Automotive suspension systems have big potential of mechanical failure due to fatigue as this system was subjected to the variable amplitude loading under service condition. This study was specifically focuses on coil spring, one of the suspension system parts. When vehicle was driven on any road surfaces and hit potholes or bump, this coil spring is then affected by the significant load. This significant load will cause the damage to this component. The objective of this study to predict the coil spring fatigue damage and then relate it with the I-kaz coefficient, results from a new statistical-based method, I-kaz method. The signal captured from this repeated loading was known as fatigue signal. The car was driven on three different roads, highway, country road and damage-surface road. The strain gauges were mounted on the outer surfaces of the coil spring to capture the fatigue load variable amplitude data on the road. The recorded strain was then analysed for fatigue damage and I-kaz coefficient purposes. From the analysis, it was found that the damage road gives the highest fatigue damage rather than the other road and also the fatigue damage was proportionally related to the I-kaz coefficient.