An Analysis by Finite Element Techniques of the Effects of a Crack in the Gear Tooth Fillet and its Applicability to Evaluating Strength of the Flawed Gears

抄録

A finite element technique was used to obtain two-demensional stress distributions in gear tooth fillets. In this study we have treated the case of a crack type flaw existing normal to the free surface at the most critically stressed point in the tensile fillet. The Mode I and Mode II stress intensity factors were computed for the leading edges of hypothetical cracks by using finite element techniques. The results show that stress intensity factors for the opening fracture mode are significantly greater than those for the edge sliding mode for all cases investigated. The computed stress intensity factors were utilized for the following purposes : 1. a simulation of crack propagation in the tensile fillet, 2. a computation of the allowable load for a gear having a crack in the tensile fillet, and 3. a computation, for a given load condition, of the residual life of a gear having a crack in the tensile fillet.