Mission profiling of road data measurement for coil spring fatigue life

This study presents the mission profiling of three road conditions to assess the fatigue life of vehicle coil spring. Identifying all the service conditions of vehicle components, which indicate different possible situations and events, is crucial for the design of such components. Analyzing loading profiles prevents the over design or under design of components, which may lead to wastage or unexpected failure. Every road condition is different because of surface roughness. Acceleration signals were collected and processed using the shock response spectrum and extreme response spectrum methods for transient and stationary events, respectively. Mission profiling was performed to synthesize the equivalent power spectrum density (PSD) load profile for different uses of roads. The resulting PSD indicated that the greater involvement of the rural road reduced the lifetime of coil spring. The synthesized PSD was validated through the mean value of the responses. Fatigue life of the spring was compared to a concatenated strain life measurement using a conservative approach. This research revealed the generation of accurate road loading profile with measurement of acceleration from different roads for spring fatigue studies.