Laser Ultrasonic System for Surface Crack Visualization in Dissimilar Welds of Control Rod Drive Mechanism Assembly of Nuclear Power Plant
Laser Ultrasonic System for Surface Crack Visualization in Dissimilar Welds of Control Rod Drive Mechanism Assembly of Nuclear Power Plant
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DOI：
10.1155/2014/296426
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发表时间：
2014-03
影响因子：
1.6
通讯作者：
Yunshil Choi;Hyomi Jeong;Jung‐Ryul Lee
中科院分区：
文献类型：
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作者：
Yunshil Choi;Hyomi Jeong;Jung‐Ryul Lee
提出了一种基于超声传播成像（UPI）技术的J型坡口异种焊缝裂纹可视化系统。一个全尺寸的控制棒驱动机构（CRDM）组件样本制造，以验证所提出的系统。在CRDM组件的反应堆容器头部的内表面的一个点处接触超声波传感器。调Q激光束被扫描以在焊缝周围产生超声波。通过超声波传播成像可以确定裂纹的位置和尺寸。此外，超声频谱成像揭示了频率成分的损伤诱导波，而小波变换的超声传播成像增强损伤的可见性，通过生成波传播视频集中在频率成分的损伤诱导波。双向异常波传播成像与相邻波减法也被开发，以提高裂纹的可见性，无论裂纹的方向和波的传播方向。总之，全尺寸试样试验表明，多损伤可视化工具是非常有效的J型坡口异种焊接裂纹的可视化。
In this paper, we propose a J-groove dissimilar weld crack visualization system based on ultrasonic propagation imaging (UPI) technology. A full-scale control rod drive mechanism (CRDM) assembly specimen was fabricated to verify the proposed system. An ultrasonic sensor was contacted at one point of the inner surface of the reactor vessel head part of the CRDM assembly. Q-switched laser beams were scanned to generate ultrasonic waves around the weld bead. The localization and sizing of the crack were possible by ultrasonic wave propagation imaging. Furthermore, ultrasonic spectral imaging unveiled frequency components of damage-induced waves, while wavelet-transformed ultrasonic propagation imaging enhanced damage visibility by generating a wave propagation video focused on the frequency component of the damage-induced waves. Dual-directional anomalous wave propagation imaging with adjacent wave subtraction was also developed to enhance the crack visibility regardless of crack orientation and wave propagation direction. In conclusion, the full-scale specimen test demonstrated that the multiple damage visualization tools are very effective in the visualization of J-groove dissimilar weld cracks.