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.Transient eddy-current technique is being developed for detection of flaws located at depth within metallic structures. It uses a transient signal to induce eddy currents, which interact with flaws in a conducting structure to produce an output signal that provides information about the flaw. The technique involves a transmission/reception probe to produce an output signal centred on a given frequency.
In this work, surface crack detection is considered through modelling of eddy-current pattern which are induced by the presence of small flaws. This was undertaken by means of the finite element method under transient inductive excitation having the form of short time pulses. The proposed model included the excitation coil, the sensing coil, the tested defected plate and the ambient air. Different types of probes were simulated by changing some of the design parameters in an attempt to generate an output signal of optimum magnitude and shape.
