铝合金焊缝裂纹的阵列涡流检测仿真研究

为了分析阵列涡流传感器扫查不同位置表面横向裂纹时的线圈输出信号特征,以及焊缝受热区金属材质变化对线圈输出信号的影响,建立铝合金焊缝裂纹的阵列涡流检测的三维有限元模型。结果表明:当裂纹长度分别为1.6、3.0、4.5mm时,裂纹长度与线圈感应电动势的波峰幅值呈单调递增关系,探头扫查侧面裂纹时的线圈感应信号总是大于正上方裂纹;焊接所引起的5A06铝合金材料电导率减小会使线圈的感应电动势幅值增大,且当裂纹长度分别为1.6、3.0、4.5 mm时,裂纹长度越大,电导率减小在裂纹检测时对线圈输出信号的影响越小。

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.