A Model-Based Analysis of Crack Fault in a Two-Stage Spur Gear System

Modelling is an important task for condition monitoring and decision making purpose of geared systems. A 10 DOF (Degree of Freedom) lumped parameter model is proposed in this paper to simulate the vibrational response of a two-stage spur gear system under healthy and faulty conditions. A quadratic path is adopted for the crack propagation through the gear tooth thickness and gear mesh stiffness for different crack lengths was calculated using the potential energy method. A set of time and frequency domain indicators were used to see their efficiency on tracking the crack fault severity. Simulation results showed that the peak value is the most sensitive time-domain indicator to the crack fault propagation. In the frequency domain, sideband peaks amplitude of the residual signal showed a good consistency with the crack length evolution.