POISSON's ratio correction in elastic analysis of low cycle fatigue

Since plastic deformation takes place with no change in volume, the equivalent variation in deformation relevant to fatigue analysis is greater than in the elastic case. Although certain codes recommend using a nominal P.R. value in calculations, it appears more convenient to apply a multiplying factor (Kv) to the equivalent variation in deformation computed under elastic conditions. It has been shown that this factor (Kv) can be derived analytically from the material cyclic curve. Diagrams can be plotted, giving (Kv) as a function of changes in deformation taking place in the plane of the wall. This correcting factor is independent from correction Ke which applies to strain amplification in stress raisers. (orig./HP)