Fracture of sandstone characterized by digital image correlation

doi:10.1016/j.ijrmms.2012.12.043

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	Fracture of sandstone characterized by digital image correlation
	Lin, Qing ; Labuz, Joseph F.
刊名	international journal of rock mechanics and mining sciences
	2013
关键词	Mode I fracture Process zone Digital image correlation Critical opening displacement Crack propagation COHESIVE-ZONE MODELS TOUGHNESS MECHANICS STRENGTH
DOI	10.1016/j.ijrmms.2012.12.043
英文摘要	Evaluation of mode I fracture characteristics, such as critical opening displacement and process-zone length, is fundamental for the analysis and prediction of crack growth. To identify deformation with micron-scale resolution, experiments were performed using digital image correlation, where displacement is determined through a comparison of a pair of digital images by matching a small area from the image before deformation to the image after deformation. The matching process uses a cross-correlation algorithm, and within this study, the correlation is based on a Fast Fourier Transform method. Mode I fracture tests were performed on Berea sandstone using three-point bending. Twelve specimens, of three types, were fabricated: six center notch (0.5 mm radius), three smooth boundary, and three reduced-section (6 or 12 mm radius notch). The characteristics of tensile fracture, namely opening displacement and crack length, were extracted from detailed displacement measurements. At the onset of unstable propagation (peak load) for the center notch specimens, the critical opening displacement omega(c)=30 mu m at the notch tip, and as the crack propagated, the known position of omega(c) allowed the identification of the process zone throughout the post-peak response. Incremental displacement contours established the tip of the effective crack, and the length of the process zone l(p)=5-7 mm, about 10 times the maximum grain size. In addition, it was observed that the process zone maintained a constant length with constant critical opening for all tests. (C) 2013 Elsevier Ltd. All rights reserved.; Engineering, Geological; Mining & Mineral Processing; SCI(E); EI; 7; ARTICLE; 235-245; 60
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/154478]
专题	工学院
推荐引用方式 GB/T 7714	Lin, Qing,Labuz, Joseph F.. Fracture of sandstone characterized by digital image correlation[J]. international journal of rock mechanics and mining sciences,2013.
APA	Lin, Qing,&Labuz, Joseph F..(2013).Fracture of sandstone characterized by digital image correlation.international journal of rock mechanics and mining sciences.
MLA	Lin, Qing,et al."Fracture of sandstone characterized by digital image correlation".international journal of rock mechanics and mining sciences (2013).