A standardizable approach for Tooth Flank Fracture

Abstract Ultrasonic scanning of large spiral bevel gears and the subsequent fracture analyses early-stage tooth flank fractures imply a mode II crack initiation under surface-parallel, orthogonal shear stresses. An iteration Dang Van criterion is presented that focuses exclusively on surface-parallel material planes, yielding standardizable approach for study in gears. It shown Van’s stress amplitude maximum hydrostatic along surface-perpendicular path can adequately be described by Hertzian Lang’s compressive residual stress. The fatigue properties same are estimated from Thomas’ hardness model augmented ISO-inspired lifetime, size conversion factors. article closes with comparison between commonly used Witzig-Boiadjiev, Hertter-Wirth, DNV subsurface herein proposed, rationalized criterion.