음향비선형 특성의 합성개구영상화 기법개발

Abstract

Acoustic nonlinearity has been widely considered as a promising tool to detect micro defect. However, still it has difficulties in the field application, since its handling is not so easier than the conventional linear method. One of solution to overcome this problem is the imaging of inspection area by electronic scan, which does not require the movement of transducer and makes it easy to find the defect by comparing the relative value of acoustic nonlinearity at defect and non-defect point. This paper reports a basic study about imaging of nonlinear acoustic characteristics on the basis of synthetic aperture method. Experimental results obtained for a contact specimen proved the possibility of the proposed method.