Characterization of Stress Concentration Degree Based on 2-Dementional Magnetic Memory Signals

Abstract

To explore a way to characterize fatigue damage degree of ferromagnetic materials by metal magnetic memory testing (MMMT), tension-compression fatigue test of specimens with different stress concentration factors made of 45% C steel were carried out. Both normal and tangential component of magnetic memory signals, Hp(y) and Hp(x), of specimens under different fatigue cycles were measured by EMS-2003 and RM-1 magnetic memory testing apparatus respectively. The results show that, the gradient variation of Hp(y) signals during the fatigue test is similar to each other, but the gradient value is different due to the different stress concentration factors. And so is the relative peak value of Hp(x) signals. Both gradient of Hp(y) and relative peak value of Hp(x) can be used to distinguish the stress concentration degree of specimens.