A dynamic model of ball bearing for simulating localized defects on outer race using cubic hermite spline

In this paper a dynamic model is presented for predicting the vibration behavior of a ball bearing under the influence of localized defects on the outer race. The calculation of contact force is based on Hertzian contact deformation theory. The pulse generated by the ball striking the defect on outer race is modeled by using the blending functions of the cubic hermite spline. The effect of change in the angular position of the defect, size of the defect on outer race, multiple defects on outer race and the variation of load on the vibration amplitude is predicted by this model. A computer program in MATLAB is developed and the governing equation of motion is solved by Euler’s method. The numerical results are presented as a function of variation of the geometry of the outer race due to the impact at the defect and normal race contact w.r.t. time and the conclusion about the health of the bearing is determined by the spectral analysis. To validate the results, experimentation has also been performed.