Effect of Vehicle Speed to the Fatigue Life of a Coil Spring Based on Strain-Life Approach

This research aims to determine the fatigue life of an automotive coil spring driven with different speeds. A strain gauge was fixed at the critical point of the vehicle driven with the speeds of less than 20 km/h, 40-50 km/h, and more than 70 km/h. The strain signals obtained were analyzed using the Coffin-Manson, Morrow, and Smith-WatsonTopper models. According to the results, the lowest fatigue life of 3.5E+8 cycles to failure was obtained at speed more than 70 km/h. This was 143 % lower than just as the vehicle was driven at the speed of 40-50 km/h, and 443 % lower at less than 20 km/h. It concluded that, as the vehicle was driven at an accelerated speed, the stress received by the coil spring was higher, thereby significantly contributing to the fatigue life of the component.