Fault diagnosis based on nonlinear dynamic modeling in rolling element bearing systems

In order to diagnose the location and size of fault in rolling element bearing system accurately, two-DOF dynamic model and six-DOF dynamic model of fault bearings are built and compared with each other based on the generation mechanism of bearing fault. The models not only consider the influencing factors of variable stiffness caused by bearing clearance, but also introduce a unit resonator to simulate high frequency inherent vibration arising with the bearing fault in six-DOF dynamic model. Dynamic models of localised fault on outer race, inner race and rolling element of rolling element bearing are simulated and analyzed by using Runge-Kutta method. The simulating results are in accordance with experimental results, which proves the accuracy and practicality of the models used in engineering application.