Prediction Of Fatigue Life And Failure Analysis Of Gear Based On Explicit Dynamics

Gear, as the most widely used transmission parts, whose failure has been the main hidden trouble of safety and reliability of equipment of the threat, and therefore must be carried out in-depth study on the mechanism of gear fault features. But the complex conditions of gear system brought great difficulties to the research on the mechanism. Therefore, the reasonable and effective simulation analysis has important theoretical research value and practical engineering value for the gear system.This paper mainly research on closed gear box based on explicit dynamics and introduce the main steps of the gear system. Putting forward using dynamic relaxation method for gear explicit analysis of process optimizationand putting forward the method of fatigue life prediction model of closed type gear box. Analysis of the influence of oil supply situation, modulus and fatigue life of the model. Variable stiffness meshing with the explicit analysis of the fault of gear, and to observe and analyze the dynamic response of the corresponding fault characteristics. The main contents are as follows:1.The gear in the gear dynamic analysis simulation system often appear on the threshold of high-frequency oscillation problem of system. An method of eliminating the initial loading of the oscillation system based on the dynamic relaxation is presented.2.Using the method of local stress and strain on the bending fatigue life of tooth root estimate. The solving steps of the local stress strain method isintroduced. Put the explicit analysis results into the fatigue analysis of nCode platform and based on the rain flow counting method, finally obtained the bending fatigue life of gear valuation3.Under the condition of isothermal lubrication taking a involute spur gear as research object,a involute spur gear contact-fatigue life model composed of the lubricated-contact analysis and the explicit analysis was established.4.To analyze the impact of contact ratio, modulus, oil supply condition on gear fatigue life using the above method. Compared with the traditional mathematical model can better reflect the effect of the dynamic characteristics of the system on the fatigue life of the explicit dynamic analysis.5.Finally, by using explicit dynamic simulation analysis of meshing stiffness of gear when the curve drawing. The establishment of the 6 degree of freedom gear system dynamics model. Analysis of the tooth root crack respectively and tooth surface spalling on the stiffness characteristics and dynamic characteristics and the tooth root crack as the object of study by verifying the results of dynamic response of the experiment.