相控阵超声绝对声时法测量底面开口裂纹

Bottom crack measurement by using AATT with ultrasonic phased array

针对工件内表面开口裂纹单面单侧定量检测困难的问题,采用相控阵超声绝对声时法(Absolute Arrival Time Technique,AATT)从单面单侧对不同厚度试块中的底面人工开口裂纹自身高度测量进行了数值仿真和实验,并对焊缝中的自然裂纹进行了AATT测量。对比AATT测量结果与常规衍射时差法超声检测(Time of Flight Diffraction,TOFD)测量结果并分析,发现AATT从单面单侧对底面开口裂纹进行定量测量可以达到与常规TOFD同样的测量精度。AATT操作简便,可单面单侧定量测量2 mm以上底面开口裂纹的自身高度。

This paper proposes an effective method of using ultrasonic phased array to measure bottom cracks from single-sided-unilateral. The heights of artificial cracks in different thickness blocks are measured by the Absolute Arrival Time Technique（AATT） with ultrasonic phased array in testing simulation and experiment. The height of natural crack in a weld is also measured by AATT. A comparative analysis of the experimental results and the conventional TOFD measurement results is conducted, and the analysis results show that the height of bottom crack can be measured quantitatively by AATT from one side and this measurement technique can achieve the same accuracy as TOFD measurement.