相控阵超声检测横向分辨力实验测试及分析

Experimental measurement and analysis of the lateral resolution of phased array ultrasonic detection

使用带有斜楔的60晶片线型阵列换能器,以扇扫成像方式,对孔径为8~30 mm范围内,焦距分别为30 mm、40 mm、60 mm、80 mm时相控阵系统的横向分辨力进行了实验测定。研究发现：焦距一定时,随线阵换能器孔径的增大,系统的横向分辨力提高;孔径一定时,随焦距增加,系统横向分辨力降低;焦距和换能器孔径对相控阵成像分辨力影响显著。实测结果与理论分析以及已有文献的数值模拟结果具有良好的一致性。研究结果对于相控阵超声检测的工程应用具有重要参考价值。

Lateral resolution of phased array is measured experimentally with the array aperture of 8 to 30 mm and focus length of 30 mm,40 mm,60 mm,80 mm,respectively.In the experiments a 60 element linear array transducer with wedge is used and sectorial scanning method is adopted.Experiment study reveals that increasing the aperture will improve the lateral resolution while the focus length is fixed;the lateral resolution will decrease with the increase of focus length while the aperture is fixed.The focus length and aperture have great impact on the resolution.Experiment results show good agreements with theoretical analysis and numerical simulation results reported in literatures.The study results are of great value to the applications of phased array ultrasonic testing.