Analytical Modelling of Surface Pitting in Simulated Gear-Teeth Contacts

Research leading to analytical modelling of surface pitting failure in contacts similar to those in spur and helical gears is reported. Development of this model is based on observations of surface pitting morphology, analysis of crack initiation and propagation for a single or a set of distributed cracks.

The morphological experiments on a geared roller fatigue tester revealed slow growing surface cracks followed by a rapid growth of a single crack leading to a pit. Near surface inclusion is found to be the cause of this rapid growth.

Models for determining the life for developing a single surface crack and for propagating this crack to form a single deep pit are also described.