Investigation of low cycle fatigue crack opening by finite element method

Abstract

This research presents the comparison the resultsobtained by the analytical, the finite element and the experimentalmethods, while studying the size of crack openingand its contour curve in case of cyclic symmetricalloading of a specimen depending on the cycle number andloading level. The experiment employs a grade 45 steelspecimen with a working part of rectangular cross-section,and with the central crack. The analytical method has beenapplied for calculations using the equations proposed byIrvin and Makhutov, and the programmable systems COSMOSWorksand ANSYS have been used for FEM. In addition,the influence of the specimen geometry on the crackopening has been taken into consideration. The resultsdemonstrate quite adequate coincidence between the resultsof experimental and finite element methods, while theanalytical calculations are accurate only at the crack tip.