Dynamic modelling and simulation of defective rolling element bearing based on Matlab/Simulink
                                                      HE Zhen zhi1, XU Xiao dong2, SHAO Ming hui1
（1.School of Mechanical & Electrical Engineering, Jiangsu Normal University, Xuzhou 221116, China;2.School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou 730050, China）


Abstract: In order to solve the problem of dynamic modelling and characteristics analysis of defective bearing, the additional contact deformation caused by scratch defect of raceway was introduced into the excitation model of defect. The relationship between additional contact deformation and defect width and bearing parameters was established based on contact mechanism theory, and then a nonlinear dynamic model of rolling element bearing with scratch defect on raceway was established. The simulation model was set up by using Matlab/Simulink, and the analysis of numerical simulation of vibration characteristics generated by scratch defects was completed to obtain the contact deformation, contact forces and vibration acceleration of outer ring. The simulation results were evaluated and the vibration of bearing with scratch on inner raceway or outer raceway were tested. The experimental results show that the normalized envelop spectrum of simulated results and experimental results are fitted well and the corresponding defect frequency and its harmonic frequencies are both found. Also there are sideband frequencies at defect frequencies in the spectrum of defective bearing with defect in inner raceway. Thus the dynamic model and simulation model were verified.
Key words: rolling element bearing; scratch defect; dynamic modelling; Simulink; numerical simulation