Journal of the Korean Society of Safety (한국안전학회지)

The Korean Society of Safety (한국안전학회)
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The Investigation for Detection of Crack Initiation in the CFRP Laminates under Flexural Loading Test

굽힘하중에서 탄소섬유 복합적층재의 균열 발생 측정에 관한 연구

  • Lee, Jun Hyuk (Department of Safety Engineering, Pukyong National University) ;
  • Kwon, Oh Heon (Department of Safety Engineering, Pukyong National University)
  • 이준혁 (부경대학교 안전공학과) ;
  • 권오헌 (부경대학교 안전공학과)
  • Received : 2022.07.27
  • Accepted : 2022.10.21
  • Published : 2022.10.31
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Abstract

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.

Keywords

Acknowledgement

This work was supported by a Research Grant of Pukyong National University(2021).

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