School of Instrument Science and Opto-Electronics Engineering, Hefei University of Technology, Hefei 230009, China.
Sensors (Basel). 2019 Nov 26;19(23):5185. doi: 10.3390/s19235185.
Shearography has been widely used in non-destructive testing due to its advantages in providing full-field, high precision, real-time measurement. The study presents a pixelated carrier phase-shifting shearography using a pixelated micropolarizer array. Based on the shearography, a series of shearograms are captured and phase maps corresponding to deformation are measured dynamically and continuously. Using the proposed spatiotemporal filtering algorithm in the complex domain, the set of phase maps are simultaneously low-pass filtered in the spatial and temporal domains, resulting in better phase quality than spatial low-pass filtering. By accumulating the temporally adjacent phase, the phase corresponding to large deformation can be evaluated; thus, large deformations can be accurately measured and protected from speckle noise, allowing internal defects to be easily identified. The capability of the proposed shearography is described by theoretical discussions and experiments.
剪切散斑干涉计量技术由于其全场、高精度、实时测量的优势，已被广泛应用于无损检测领域。本研究提出了一种基于像素化微偏光阵列的像素化载波相移剪切散斑干涉计量技术。基于剪切散斑干涉计量技术，我们可以动态、连续地捕获一系列剪切图像，并测量相应的变形相位图。通过在复域中使用所提出的时空滤波算法，我们可以同时对相位图进行空域和时域的低通滤波，从而获得比空域低通滤波更好的相位质量。通过累积相邻的时域相位，可以评估对应于大变形的相位，从而可以准确测量大变形，并保护其免受散斑噪声的影响，使得内部缺陷能够被轻松识别。通过理论讨论和实验，描述了所提出的剪切散斑干涉计量技术的性能。
