Simulation and experimental study of remote field current testing for hidden defects of aluminum alloy plate with damping coating

Abstract

Purpose Detection of hidden defects of aluminum alloy plate with damping coating is a challenging problem. At present, only a few non-destructive testing methods exist to address this engineering problem. Without the restriction of skin effect, remote field eddy current (RFEC) overcomes the interference caused by the damping coating. The RFEC, which has potential advantages for detecting the hidden defects of aluminum plate with damping coating, can penetrate the metal plate to detect buried depth defects. This study aims to test how thick the RFEC sensor can penetrate the metal plate to detect the buried defects. Design/methodology/approach The magnetic field distribution characteristics are analyzed, the magnetic field intensity distribution is calculated, and the structure and parameters of the coil, magnetic circuit and shielding damping are determined through the two- and three-dimensional finite element simulation methods. Optimal excitation frequency is obtained, and the distance between the excitation coil and detection coil is determined by analyzing the relationship between excitation frequency and remote field points. Findings Simulation and experimental results verify the feasibility of applying the RFEC detection technology in detecting the hidden defects of aluminum alloy plate with damping coating. Originality/value In this paper, the RFEC testing model of hidden defects in aluminum plate sample with damping coating is established by using the finite element method.

Implementation of Magnetic Markers for the Diagnostics of Conveyor Belt Transportation Systems

“…The main advantages of magnetic sensing lie in the possibility of contactless sensing, the possibility of the nondestructive diagnostics or inspection, and the reliability of the obtained data. Therefore, attention in this area is paid to the development of different types of magnetic sensors based, for example, on eddy current sensing [31], the giant magnetoresistance phenomenon [32], or electromagnetic encoders [33], and also related methods used for increasing the resolution of obtained data [34,35] to reveal hidden defects [36] and damage [37] of different materials.…”