Improvement for optical mechanics method of coherent gradient sensing
Improvement for optical mechanics method of coherent gradient sensing
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DOI：
10.1016/j.ijleo.2009.05.019
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发表时间：
2010-11
期刊：
影响因子：
3.1
通讯作者：
W. Xu;Yaping Zhang;R. Guo
中科院分区：
文献类型：
--
作者：
W. Xu;Yaping Zhang;R. Guo
相干梯度传感（CGS）是一种双光栅横向剪切干涉技术，具有光学系统简单、非接触、实时、全场光学信息和分辨率可变等优点，在均质材料和复合材料的准静态和动态裂纹尖端场研究中得到了广泛的应用。它可以在反射模式（不透明材质）和透射模式（透明材质）下使用。CGS干涉图像中条纹级数的准确性将直接影响实验研究的精度。由于光学原理与其他光学方法的不同，CGS的条纹阶数无法通过相移技术得到。本文介绍了一种改进的CGS方法，并对其进行了分析，该方法能够准确地获得CGS干涉图像中任意位置的条纹阶数。这种方法不需要额外的光学装置和复杂的图像处理技术，而只需要在不同的负载下的几个（大于两个）CGS干涉图像。静态断裂实验表明，该方法能明显提高CGS方法的精度。
Coherent gradient sensing (CGS) is double grating lateral-shearing interferometric technique with the simplicity of the optical set-up, non-contact, real-time, full-field optical information and variable resolution, which has shown many applications in the study of quasi-static as well as dynamic crack-tip field in both homogeneous and composite materials. It can be used both in a reflection mode (for opaque materials) and in a transmission mode (for transparent materials). The accuracy of the fringe order in the CGS interference image will deeply influence the precision of experimental study. Because of the difference in the optical principle from other optical methods, the fringe order of CGS cannot be obtained through the phase-shift technology. In this paper, a kind of modified CGS method is introduced and analyzed, which can accurately obtain the fringe order of random position in the CGS interference image. This method does not need additional optical set-up and complicated image processing techniques, but only needs several (greater than two) CGS interference images under different loadings. Static fracture experiments show that this method can evidently improve the precision of the CGS method.