A new incremental fatigue method

By analyzing the material's strain-life data differentially, this paper brings to light the generally overlooked incremental damage concept which underlies the conventional uniaxial rainflow counting algorithm and the strain-based fatigue method. This incremental damage concept not only allows the uniaxial rainflow program to be logically extended to multiaxial problems, it also forms the basis for a new incremental fatigue damage accumulation method. Several simple examples, including a multiaxial rainflow algorithm, are given to illustrate how the new approach can be applied to general multiaxial problems and how it can be formulated so that any chosen uniaxial model using the traditional parametric approach can be closely reproduced.