| 摘要 |
The magnetoelectric coefficient in iron-based alloys has a stress value of about 0.6 of that of the elastic limit. A reversal in sign is caused by structural phase slip which is the basis for the onset of metal fatigue. Based on this phenomenon, a method is provided for determining the onset of metal fatigue. The method includes applying a periodic mechanical stimulus at a given frequency to a test structure, and using a magnetometer, sensing the magnetic field of said structural element during the application of stimulus, and then determining whether or not there is a 180 degree difference between the phase of the stimulus and that of the magnetic response for various regions of the test structure.
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