Fatigue Life Prediction Of Rolling Bearing Based On Damage Mechanics

As the key component of the rotating machinery,the reliability of the rolling bearing is directly related to the normal operation of the important rotating machinery,such as aero engine.The effective prediction of the life of rolling bearing has very important theoretical significance and practical value of engineering.The life prediction of rolling bearing based on damage mechanics combines the mechanical mechanism of the actual rolling bearing failure.Therefore,the exfoliation failure model based on the damage mechanics is more advantageous in theory.In this paper,based on the damage mechanics finite element method,the life prediction of the most widely used deep groove ball bearing in rolling bearing is studied.The main tasks are as follows:(1)Based on the principle of elastic mechanics and damage mechanics,a contact fatigue model of rolling bearings is derived based on the mechanism of fatigue damage of rolling bearings.According to the torsional S-N curve of the bearing steel GCr15,the parameters of the material in the contact fatigue model of the rolling bearing with coupled damage are calculated.(2)According to the theory of Hertz contact,the theoretical formula of contact stress for point contact ball bearings is derived,and the contact stress distribution of rolling bearings is obtained through theoretical and simulation methods.Through the analysis of the contact stress zone,it is further verified that the fatigue damage of the rolling bearing is mainly caused by the alternating shear stress.(3)Based on the torsional S-N curve of the bearing steel GCr15 material,the correctness of the contact fatigue model of the rolling bearing with coupled damage is verified by the simulation.(4)The contact fatigue model of rolling bearings based on coupling damage is applied.The life of 6206 ball bearings under different conditions is calculated by two dimensional rolling bearing model.The influence of radial load,lubrication condition,bearing defect,ball number and speed on the life of rolling bearings is analyzed.(5)The fatigue strengthening test of rolling bearing was carried out,and 6206 bearings with artificial defects were selected to test the 6206 bearing and the inner raceway respectively.The initial fatigue peeling position of the test bearing verified the results of the bearing stress simulation.The test life of the bearing and the life of the simulation have obtained good precision,which verifies the correctness of the results of the simulation model.