Today, the need to produce materials and products that are reliable and durable present ongoing challenges for manufacturers and material suppliers. Consumer safety concerns and increased worldwide awareness by governmental, regulatory and technical forums are important considerations.
Multi-million cycle tests are typical and fatigue test systems capable of repeatedly performing 400M-600M cycle tests are in increased demand. In such tests, high-cycle and high-frequency fatigue testing is often desired in order to minimize the cost and length of testing activity. Prediction of fatigue life requires experimental measurement of load variability to determine stress levels as a function of the number of cycles. Fatigue life is based on the number of cycles a material or component will experience at a given stress level under simulated environmental or use factors.
Typical SN curves are generated as an outcome of the fatigue testing activities. Strain measurement may or may not be performed in addition to controlling the load levels. Where load measurement is not available, the test may be performed under strain control as the means to establish representative stress levels.