Determination of the plastic zone by laser-speckle correlation

1991 ◽  
Vol 31 (4) ◽  
pp. 348-352 ◽  
Author(s):  
Y. Z. Dai ◽  
C. J. Tay ◽  
F. P. Chiang
Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4728
Author(s):  
Wenxin Hu ◽  
Zhipeng Sheng ◽  
Keyu Yan ◽  
Hong Miao ◽  
Yu Fu

The laser speckle correlation method has found widespread application for obtaining information from vibrating objects. However, the resolution and accuracy of the laser speckle correlation method as they relate to the defocusing degree have not been analyzed sufficiently. Furthermore, the possible methods for speckle pattern quality assessment and enhancement have not been studied. In this study, the resolution and accuracy of the laser speckle correlation method are analyzed, and it is found that they are affected by the defocusing degree and speckle pattern quality, respectively. A new speckle pattern quality criterion combining the mean intensity gradient and frequency spectrum was proposed, called CMZ. The quality of the speckle pattern is higher when the CMZ is closer to zero. The proposed criterion was verified by simulated speckle patterns and real speckle patterns with different speckle sizes, densities, and gray contrasts. In the experimental setup stage, a suitable defocusing degree can be selected based on the resolution requirement and optimal speckle size, and other experimental parameters can be determined according to the CMZ criterion. Rotation and vibration experiments verified the effectiveness of the laser speckle correlation method and confirmed the reliability of the experiment preparation based on proposed CMZ criterion.


2006 ◽  
Author(s):  
Mikael Sjödahl ◽  
Per Gren ◽  
Istvan Sárady ◽  
Natalia Miroshnicova

Measurement ◽  
2021 ◽  
pp. 110490
Author(s):  
Vismay Trivedi ◽  
Swapnil Mahajan ◽  
Mugdha Joglekar ◽  
Nirav Joshi ◽  
Vani Chhaniwal ◽  
...  

2021 ◽  
Vol 46 (20) ◽  
pp. 5083
Author(s):  
Zhou Ge ◽  
Yizhao Gao ◽  
Hayden K.-H. So ◽  
Edmund Y. Lam

Sign in / Sign up

Export Citation Format

Share Document