ABSTRACT
The fatigue failure of a machine part under loading is contingent first and foremost on the stresses and strains within. The theoretical foundation used for fatigue analysis involves two attributes created by stresses: an elastic state existing below the yield point of the material and a plastic state existing above it. Our introduction here of corresponding theories of elasticity and plasticity is of a limited scope and is directed mainly to enable one to understand the computational methods used in fatigue analysis.
