Research On Vibration Fatigue Mechanism And Application Of Component

Component is one of the most basic components of the mechanical system and structure. The vibration fatigue of the component not only affects the normal work, but also directly related to the safety and reliability of the whole system. Therefore, it is urgent to carry out the research on vibration characteristics, fatigue crack growth mechanism and life estimation of the components to ensure the safe and efficient operation of mechanical systems and structures. The purpose of this paper is to solve the essential problems about the influence of vibration characteristics of the members on the fatigue crack growth law, the main contents include the following:An analysis method of fatigue crack growth rate based on vibration characteristics is presented. First, dynamic stress amplitude, the important control parameters of the vibration fatigue crack propagation, is introduced by studying the internal mechanism of vibration and fatigue. Then, according to the periodic vibration dynamic response characteristics and driven dynamic stress response, a half-wave harmonic vibration processing method is proposed, and a fatigue crack growth rate model with different vibration characteristics, considering the crack closure effect and effective stress intensity factor, is established.According to the process characteristics of half-wave harmonic vibration, based on vibration fatigue crack growth rate model, combined with crack propagation synchronization analysis method, and considering the influence of the order and the average amplitude of vibration, a series of estimation models of dynamic crack size, vibration fatigue damage and fatigue life based on vibration characteristics are presented, and through an example to verify.Based on the theory of vibration fatigue models and put the GUI function module of MATLAB software as the carrier, a kind of virtual vibration fatigue test is established, and a simple simulation system is developed, which can quickly and effectively reflect the dynamic changes of the vibration fatigue crack and the life estimation.With crack component of elastic linkage mechanism system as the simulation object, according to the theory of half-wave harmonic vibration and use the virtual vibration fatigue test, the vibration fatigue crack propagation law and vibration fatigue life of the system under different conditions are simulated and analyzed, and some useful conclusions are obtained.