Reliability calculation model of gears considering strength degradation

The correct evaluation of reliability for the system or components is very important for high quality and security. The traditional models take stress and strength as the static random variable without considering the effect of strength degradation. The effect of strength degradation on the reliability of a gear was studied in this paper. With the conditional reliability introduced, a reliability calculation model of gear with multiple failure modes is developed by using the stress-strength interference model, without the assumption that there was independent failure mode of gear. The reliability model of a gear under the strength degradation is developed based on the model. And the dependence of gear reliability on the strength degradation is studied. The result shows that the gear reliability decreases with the strength degradation due to fatigue, corrosion, aging and other factors.