Transient Eddy Current Field due to a Tilted Circular Coil Above a Plate Conductor

This paper investigates the electromagnetic field due to a tilted circular coil with a pulsed excitation current above a conducting plate of finite thickness. The current density expression for the tilted circular current-carrying coil is derived and the eddy current density induced within the conductor is analytically calculated, then an effective method for computing the time-domain response is proposed. Some examples are given at last, and the temporal and spatial characteristics of the transient eddy currents and the relationship between the response and tilt angle, plate thickness are discussed. The results show that the method in the paper can be used for the analysis of the linear transient eddy current field due to a tilted circular coil. The model and method here are validated by comparison with the simulation result from software. These results could assist in understanding the acquired pulsed eddy current test signals under conditions of tilt.