NUMERICAL STUDY ON METAL MAGNETIC MEMORY TECHNIQUE

Metal magnetic memory (MMM) technique can be effective in determining the initial damage of materials and structures in service and partly applied in engineering. However, no quantitative relations between MMM signals and the stress states have been reported. Numerical method is applied in this study to simulate the magnetic flux leakage (MFL) signals, which is received by considering the change of the magnetic permeability in stress concentration zone (SCZ). Systematic analyses are performed about the MFL signals affected by SCZ width, its location and the lift-off value of sensors. The results would be helpful in promoting the quantitative research of MMM technique.