Abstract
Measurement of fatigue crack growth properties is difficult by relation of accuracy and device characteristic. Non-contact and the highly precise measurement are expected by the use of a magnetostriction effect to apply in this study. The small crack growth properties and crack length measurement by a magnetic field change with the magnetostriction effect that was one of a characteristic of magnetism of ferromagnetic substance was studied. Using a coil, a magnetic field change with magnetostriction effect was detected, and the waveform change of the output was inspected The experiment result was revealed that the small crack affects a magnetic field change by a magnetostriction effect and the crack length can measure by output of a coil.
