How is component fatigue testing performed and validated?

Component fatigue testing applies repeated loads simulating customer usage until failure or completion of target life. Process includes: Defining load spectra from vehicle-level road load data, designing fixtures replicating mounting conditions, applying loads using servo-hydraulic actuators, monitoring crack initiation and propagation, and comparing results against design targets. Validation involves correlation between rig tests and vehicle durability, ensuring rig reproduces field failure modes. Statistics from multiple specimens establish reliability confidence. Accelerated load levels may be used with appropriate damage calculation adjustment.