미소균열 측정에 대한 DIC 스펙클 형상의 영향

• Published in: 한국안전학회지 Vol. 34; no. 4; pp. 15 - 21
• Main Authors: 이준혁, Jun Hyuk Lee, 권오헌, Oh Heon Kwon
• Format: Journal Article
• Language: Korean
• Published: 한국안전학회 31.08.2019
• Subjects: crack measurement; digital image correlation; displacement; gray level co-occurrence matrix; speckle pattern; 안전공학; displacement; gray level co-occurrence matrix; digital image correlation; speckle pattern; crack measurement
• ISSN: 1738-3803; 2383-9953
• DOI: 10.14346/JKOSOS.2019.34.4.15

In order to secure the safety of various machinery, it is very important to develop a technique for accurately and quickly measuring the cracks generated in the mechanical equipment and evaluating the mechanical characteristics. The evaluation of the mechanical properties is accompanied by an appropriate strain measurement according to the material and crack occurrence of the target structure. Especially, when micro cracks are generated, the evaluation method is very important. Digital image correlation is an optical full field displacement measuring method which is using currently with speckles in the interested area. However the evaluation method and conditions of image distributions have to be considered carefully to measure the crack occurrence because the images of the speckle patterns affect the quality of displacement results. In this study, the speckle pattern density is characterized to improve the accuracy of the measurement method. And also the micro crack initiation is detected by the measured displacement in the adopted speckle pattern distribution. It is shown that the proposed method is useful to determine the density pattern distribution for the accurate measurement and crack detection.