Research On Magnetic Memory Effect And Its Counter-question Of Fatigue Accumulation Damage Based On Stationary Wave

In industry, about over 80% damages of the oscillatory components under dynamic loads are caused by the fatigue failure, but with traditional NDT methods, the damages can't be tested and evaluated before the fatigue crack coming into being, which result in serious accident in the long period running of these equipments. Study results indicate that the magnetic memory effect is accumulated in the course of the fatigue accumulation damage, we can detect the fatigue damage of oscillatory component in the service forepart with magnetic memory characteristics of oscillatory components. But so far, the magnetic memory effect of oscillatory components has not been studied enough, which embarrasses the application and development of magnetic memory testing technique. The aim of the paper is that providing evaluation evidences to find early the place and degree of fatigue accumulation damage through researching the relation between fatigue accumulation damage and magnetic memory effect based on stationary wave.The fatigue accumulation damage of the component has something to do with its model,different model causes different damage speed on the component which will show different magnetic memory characters.The paper build the mathematics model of wave shape of orders con- wave and accumulation damage distribution on several boundary conditions, combining theory deducing, simulation analysis and experiment validation ,deducing the relation among fatigue accumulation damage degree, damage speed and magnetic memory characteristic parameters. At last, simulation experiment system is used to validate and perfecte the theoretical results. The purpose is reached that diagnosing early accumulation damage components with magnetic memory method. The contents of the paper are as follows.1. Based on magnetic domain energy theory, magnetomechanical effect of single cycle load is studied and it is analysed emulationally that magnetic memory characteristic parameters of single cycle load. Magnitude and direction of accessional magnetic intensity are made sure of the ferromagnetism material derived from single cycle load. Also, the relation is built between stress and magnetic memory characteristic parameter, and measurement of magnetomechanical effect is reached.