Space resolution of adjacent reverse-side cracks using rotational magnetic flux sensor and neural network

Abstract

Nondestructive Evaluation (NDE) is very useful technology to prevent accidents. Since previous magnetic sensors for NDE cannot clearly distinguish adjacent reverse-side cracks on a metallic plate, existence of adjacent reverse-side cracks is a serious problem. Up to now, there are not many discussions about space resolution of the magnetic sensor. So, it is important that adjacent small reverse-side cracks are clearly resolved in to two cracks by the magnetic sensor. The rotational magnetic flux sensor with a differential search coil is characterized by the rotational excitation and three differential output signals. And, it shows high sensitivity and high signal-to-noise ratio (S/N) to detection of a small reverse-side crack on a 5 mm thick steel plate (SS400). In this paper, we present the new NDE system such as the rotational magnetic flux sensor with the differential search coil with the neural network. And, space resolution of this NDE system is discussed. It can clearly separate adjacent reverse-sid...