METHODS FOR FATIGUE DAMAGE ASSESSMENT UNDER STOCHASTIC AND VARIABLE AMPLITUDE LOADING – A REVIEW AND COMPARATIVE ANALYSIS

Abstract

This paper presents the fundamental methods employed for fatigue damage assessment under cyclic loading, as utilized in contemporary engineering practice. Classical approaches based on S–N curves and the Palmgren–Miner linear damage rule are reviewed, along with modern techniques for processing variable amplitude loading, such as the Rainflow cycle counting algorithm and spectral methods. The underlying principles, advantages, and limitations of the various approaches are analyzed, as well as their application to the evaluation of the operational durability of engineering structures. The conducted review demonstrates that the selection of an appropriate method for fatigue damage assessment is contingent upon the nature of the loading, material properties, and service conditions. Current trends are directed toward enhancing the accuracy of residual life predictions through the integration of experimental, numerical, and probabilistic models.