定量监测裂纹涡流传感器阻抗特性研究

Research on Trans-impedance Property of Eddy Current Sensor for Quantificationally Monitoring Crack

为了提高环状涡流柔性传感器的裂纹监测灵敏度,首先分析了提离距离和材料电导率对传感器阻抗的影响,然后搭建实验系统证明了传感器模型的正确性;进而建立了提离距离和材料电导率双参数跨阻抗网格图,并对系统监测2A12-T4铝合金材料的工作频率进行了优化。结果表明:在双参数跨阻抗特性网格图中,网格面积越大,该网格对应参数条件下监测灵敏度越高;相交曲线夹角越接近90°,双参数对系统输出影响的独立性越好。预制裂纹监测试验表明,基于分段监测理念的环状涡流传感器具备识别和定量监测裂纹的能力。

In order to increase the crack monitoring sensitivity of the cyclic flexible eddy current sensor, the effects of the lift- off and material conductivity on the sensor＇s trans-impedance were analyzed, and the experimental system was established to prove the correctness of the sensor model.Furthermore,the lift-off and material conductivity double parameters trans-impedance grid pattern was proposed, and the system work frequency of monitoring 2A12-T4 aluminum alloy material＇s crack was optimized.The resuits show that in the double parameters trans-impedance grid pattern, the greater the grid area is, the higher the crack monitoring sensitivity under corresponding parameters condition will be.When the cross curve angle is closer to 90°, the influence of the two parameters on the output signal is more irrelevant.Prefabricated crack monitoring test results prove that the sensor based on the segment-monitoring method has the capability of recognition and qUantificationally monitoring crack propagation.