굽힘하중에서 탄소섬유 복합적층재의 균열 발생 측정에 관한 연구

• Published in: 한국안전학회지 Vol. 37; no. 5; pp. 7 - 13
• Main Authors: 이준혁, Jun Hyuk Lee, 권오헌, Oh Heon Kwon
• Format: Journal Article
• Language: Korean
• Published: 한국안전학회 31.10.2022
• Subjects: CFRP laminate; crack initiation; DIC evaluation; flexural loading; flexural loading; DIC evaluation; crack initiation; CFRP laminate
• ISSN: 1738-3803; 2383-9953

Digital image correlation (DIC) is a method used to measure the displacement and strain of structures. It involves transforming and analyzing images before and after deformation using correlation coefficients from irregular light and shade on the surface of structures. In the present study, a microspeckle pattern was applied to the surface of a specimen to identify initial cracking. The test specimen constituted CFRP composites laminated on a curved Al liner The specimen was manufactured by stacking 100 ply of CFRP prepregs in the 0° and 90° directions in a three-point bending test. The equivalent strain was evaluated through DIC analysis after monitoring deformation using a CCD camera. Fracture shape was observed using a microscope. The equivalent strain contour distribution was checked until the maximum load fracture occurred at the center of the test specimen. Variations in the strain indicated the initial occurrence and progression of microcracks. These results can be used to improve the accuracy of detecting micro crack initiation and to achieve structural stability.