SIMULATION ANALYSIS OF MAGNETIC SENSOR FOR NONDESTRUCTIVE TESTING BY BOUNDARY ELEMENT METHOD

This paper describes the nondestructive testing which employs the eddy currents in the substance In order to develop the magnetic flaw detection. it is important to clarify the behaviour of the field inside of the substance. In this paper. the magnetic flaw detection process is analyzed by the boundary element method taking external secondary electric circuits as well as eddy currents into account. Furethermore. we confirm the error which depends on the narrow air gap and the movement of the sensor. The boundary element subdivision according to the movement is investigated in order to decrease the error. The analytical results are shown good agreement with the measurement results. The investigation about the dimension of the flaw indicates available for the estimation of flaw from the output voltage pattern. © 1990, IEEE. All rights reserved.