Low cycle fatigue in push-pull and torsion tests: numerical prediction and experimental results

A research method has been developed for prediction of life endurance of large shafts bearing variable torsional loadings like those of the electric utility industries. Several programs are proposed to calculate damage for complex loading histories and component geometries. Torsion and push–pull fatigue tests were conducted in strain control at constant strain amplitude as a local strain approach was used in the numerical programs arrangement. Torsion tests were made on both solid and hollow specimens. Cyclic and fatigue (strain–life) curves are drawn for torsion and push–pull tests. An attempt to give an alternative correlation of results was made on the basis of Novozilov and Romanov's theory. During tests, the bending strain on the specimen was controlled in both torsion and push–pull tests.