Effect of Road Surface Contour to the Fatigue Life of a Coil Spring Based on Strain-Life Approach

Abstract

This study aims to determine the effect of road surface contours to the fatigue life of an automotive coil spring. A strain gauge was affixed at the critical point based on the stress distributions. The vehicle passed smooth and rough roads with the speeds above 30 km/h and less than 20 km/h, respectively. The strain signals obtained were analyzed using the Coffin-Manson, Morrow, and Smith-Watson-Topper models. According to the analysis, when the vehicle passed the rough road, the coil spring received a higher stress leading to a shorter fatigue life, of 1,284 cycles to failure. This value was 526 % lower compared to the smooth road because it consisted of bumps and holes.