磁歪特性を利用した周辺磁場計測による微小き裂情報の測定

抄録

Small fatigue crack closure is observed as a thing with a possibility that the influence of change of the stress level and a stress ratio, etc. to the crack growth behavior can be explained, and until now various researches have been done. Although there is a method using the strain gage as the dynamic measurement method required for the elucidation of a minute fatigue crack, in respect of generating of minute fatigue cracks being directly contacted to a measuring object thing, and there is a problem in durability or measurement of the crack growth behavior, it may not necessarily be effective. Then, its attention was paid to the magnetostriction effect which is one of the magnetic actions of a ferromagnetic substance. Measurement of micro fatigue crack information under dynamic load without requiring a simple device and contact with the object was carried out and the change in the magnetic field around the test piece due to the magnetostrictive effect was measured using a coil. We investigated micro fatigue crack information from the information.