在役枞树型叶根原位相控阵超声检测技术

In-situ phased array ultrasonic testing technology of in-service fir tree leaf roots

在役原位检测时,叶根结构复杂,检测空间受限,目前的检测方法无法保证对叶根的全覆盖检测,故提出了基于相控阵超声技术的叶根检测方法。借助非接触光学三维扫描及处理软件对叶根结构尺寸进行快速建模,再利用Civa软件对叶根内弧、外弧以及平台等相控阵探头可放置区域的检测角度进行声学仿真计算,开发了3D枞树型叶根相控阵超声组合检测工艺,并对叶根不同区域的检测覆盖和检测灵敏度进行验证研究。研究结果表明:借助光学三维扫描和Civa声学仿真计算可有效解决枞树型叶根无损检测工艺开发难题;采用相控阵超声S扫描图,结合叶根剖面图可有效判别叶根第1齿根处的缺陷;按照该相控阵组合检测工艺检测出的缺陷信号信噪比高,定位精准,能有效实现在役叶根原位检测。该文研究成果对于复杂结构部件的检测工艺开发具有重要的借鉴意义,对相控阵超声技术在汽轮机叶根在役检测工程应用具有较大的参考价值。

During in-service in-situ inspection,the structure of leaf roots is complicated and the inspection space is limited.Current inspection methods cannot guarantee full coverage inspection of leaf roots.A leaf root inspection method based on phased array ultrasonic technology is proposed.Use non-contact optical three-dimensional scanning and processing software to quickly model the size of the blade root structure,and then use Civa software to perform acoustic simulation calculations on the detection angles of the phased array probes such as the inner arc,outer arc,and platform of the blade root.The 3D fir-tree-shaped leaf root phased array ultrasonic combined detection technology was developed,and the detection coverage and detection sensitivity of different areas of the leaf root were verified.The research results show that:(1)The use of optical three-dimensional scanning and Civa acoustic simulation calculation can effectively solve the problem of non-destructive testing process development of fir tree-shaped leaf roots;(2)The phased array ultrasonic S-scan image can be effectively distinguished in combination with the leaf root profile;(3)The defect signal detected by the phased array combined detection process has a high signal-to-noise ratio and accurate positioning,which can effectively realize in-situ detection of in-service leaf roots.The research results of this paper have important reference significance for the development of inspection technology for complex structural components,and have a great reference value for the application of phased array ultrasonic technology in the in-service inspection of steam turbine blade roots.