Fatigue-life prediction using local stress-strain concepts

A cumulative-damage approach for predicting fatigue-crack initiation in engineering structures subjected to random loading is outlined. This procedure is based on the assumption that if the stresses and strains at the critical location in a structure can be related to the cyclic stress-strain properties of smooth laboratory specimens, the crack-initiation life in the structure will be the same as the specimen. A flow diagram, indicating the steps required for implementing this procedure on a high-speed digital computer, is discussed in detail.