Residual Strength Approach to Fatigue Design and Analysis

Abstract

Standard fatigue design procedures are often simply based on the endurance of a component, that is the number of cycles to cause the component to fracture at the peak of the cyclic load. Therefore, these procedures are of little value in assessing the effect of overloads on the strength of structures that have been subjected to fatigue loads, or in assessing the performance of an existing structure prior to fracture through fatigue. A fatigue methodology is developed that is based on the residual strength of a component during cyclic loading and not on the endurance. Hence, this procedure can be used to assess the remaining strength and endurance of a structure that has been subjected to cyclic loads, the effect of remedial work on the structure, as well as provide a more accurate design procedure based on the true performance of the structure.