Three-dimensional modeling of non-planar fatigue crack growth in spur gear tooth using tetrahedral finite elements

Abstract

In this paper, a numerical methodology for prediction of crack growth path and life of structures containing cracks and its application to three different case studies on spur gear tooth are presented. Three-dimensional non-planar fatigue crack propagation analyses are carried out using FRAC3D, which is part of Fracture and Crack Propagation Analysis System (FCPAS), employing fully unstructured tetrahedral elements along the crack front and in the whole model. Fatigue crack growth path predictions are performed using recently developed crack growth criteria that combine different equations used to predict crack deflection angle and to determine equivalent stress intensity factor. Comparisons of obtained results from numerical simulations with available data from the literature in terms of crack growth trajectories show very close agreement. Therefore, it is concluded that FCPAS is capable of performing three-dimensional non-planar crack growth modeling using fully tetrahedral elements in the whole finite element model, which requires less user intervention, time and effort for modeling. Moreover, the presented methodology and the recently developed crack growth criteria can be used for three-dimensional crack growth analysis.