Simulation on Al-alloy Weld Cracks Detection Based on Eddy Current Array Testing

A finite element eddy current array testing model of Al-alloy fusion weld component with cracks is established in order to analysis characteristics of output signal and effect of output signal as weld thermal damage area material change when the eddy current arrayed sensors test different transverse surface crack. The results show that when cracks lengths are 1.6 mm, 3.0 mm or 4.5 mm, the peak value of probe-coil induced emf increases with the increasing of crack lengths.The output signal of crack side face the weld always greater than the output signal of crack right above the weld when the probe scan the weld. The probe-coil induced emf will increasing because of decreases the 5A06 aluminum alloy material conductivity. And when cracks lengths are 1.6 mm,3.0 mm or 4.5mm,with the increasing size of the cracks, the influence of the induced emf amplitude of the probe-coil is also decrease because of decreases the conductivity.