材料电导率对圆台状脉冲涡流差分传感器检测信号的影响

摘要

当采用圆台状脉冲涡流差分传感器进行检测时,检测信号特征会受试件电导率的影响,为研究电导率对该传感器检测信号特征的影响规律,建立了圆台状差分传感器检测缺陷的有限元模型,仿真分析了电导率对激励线圈顶部与底部磁场变化的影响规律,并研究了电导率对差分检测信号特征的影响,最后通过实验对仿真分析结果进行了验证.研究结果表明:当电导率不同时,圆台状传感器激励线圈顶部与底部各磁场检测信号在上升阶段存在明显的差异,且随着电导率的增加,检测信号曲线在上升阶段上升的速度会降低,此外差分检测信号的峰值也会随着电导率的增加而增大.%When the cone-shaped pulsed eddy current differential sensor is used to test defects,the test signal feature can be influenced by the conductivity of specimen.In order to study the influence of specimen conductivity on the test signal feature of cone-shaped pulsed eddy current differential sensor,the finite element model of cone-shaped differential sensor was established. Then the electromagnetic at the top and bottom of the excitation loop was analyzed by the finite element model,and the influence of specimen conductivity on the differential test signal feature was studied.Lastly,the simulation result is verified by the experi-ment.The experiment result indicates that the test signal at the top and bottom of the excitation loop is different in the rising stage when the conductivity of specimen is different,the rising velocity of the test signal in the rising stage will debase when the con-ductivity of specimen augment,and the peak value of differential test signal will augment when the conductivity of specimen aug-ment.