Fatigue Life Assessments of the SAE 5160 Carbon Steel Subjected to Uphill and Downhill Roads Strains

Abstract

This study examines the fatigue life of the SAE 5160 carbon steel as the material for an automotive coil spring subjected to road strain. The strain signals were acquired by attaching a strain gauge on the component, driving a car up- and down-hill roads. The results of the fatigue life assessment based on the strain-life approach show that the downhill road resulted in a lifespan of 15,000 cycles to failure, which was 53% lower than the uphill road. This value was a result of braking when the vehicle is moving downhill, causing stress to the component leading to shorter fatigue life.

Stress Analysis on an Automotive Coil Spring Driven on Flat, Uphill, and Downhill Road Surfaces

“…The critical point due to the load of the three types of the surface was at the same point, on the inside of the second coil from above which is shown in red. This stress hotspot was close to that found in static analyses by Putra et al [13]. However, the maximum stress values differed significantly.…”