Real-time computerized tomography (CT) experiments on limestone damage evolution during unloading

被引：105

作者：

Zhou, X. P. ^{[1
]}

Zhang, Y. X. ^{[1
]}

Ha, Q. L. ^{[1
]}

机构：

[1] Chongqing Univ, Sch Civil Engn, Chongqing 400045, Peoples R China

来源：

THEORETICAL AND APPLIED FRACTURE MECHANICS | 2008年 / 50卷 / 01期

基金：

中国国家自然科学基金;

关键词：

CT images; CT values; unloading; damage model; failure criterion;

D O I：

10.1016/j.tafmec.2008.04.005

中图分类号：

TH [机械、仪表工业];

学科分类号：

0802 ;

摘要：

The computerized tomography (CT) images and CT values for the process of unloading, micro-cracking, and dilation up to the failure of limestone specimens under different unloading levels have been obtained by using the real-time CT technique. Clear CT images and CT value of the stages from compression of micro-cavities -> emergence of micro-cracks -> bifurcation -> development -> coalescence -> suddenly collapse -> rapid stress drop -> unloading can be observed. The CT value, equivalent to rock density in the CT scan layer, is the most important parameter describing the damage evolution process of rock. The paper reveals that the mechanical behaviors of rock under unloading are different from those under loading due to its load-path dependency. It is clear from the experiment that it is easy for failure phenomenon of rock to happen suddenly under unloading. The mechanism of damage evolution of limestone is analyzed. Moreover, a damage model based on CT value and a new failure criterion are established. (C) 2008 Elsevier Ltd. All rights reserved.

引用

页码：49 / 56

页数：8

共 22 条

[1] Quantifying progressive pre-peak brittle fracture damage in rock during uniaxial compression [J].

Eberhardt, E ;

Stead, D ;

Stimpson, B .

INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES, 1999, 36 (03) :361-380

[2]

Ge XR., 1999, Chin J Rock Mech Eng, V18, P497

[3]

Griffith A.A., 1921, Philos. Trans. R. Soc. Lond. Ser. A, Contain. Pap. A Math. Or. Phys. Character, VA221, P163, DOI DOI 10.1098/RSTA.1921.0006

[4]

HA QL, 1998, JOINTED ROCK MASSES

[5]

HOLCOMB DJ, 1990, ROCK MECH CHALLENGES, P645

[6] Three-dimensional observations of faulting process in Westerly granite under uniaxial and triaxial conditions by X-ray CT scan [J].

Kawakata, H ;

Cho, A ;

Kiyama, T ;

Yanagidani, T ;

Kusunose, K ;

Shimada, M .

TECTONOPHYSICS, 1999, 313 (03) :293-305

[7]

Lemaitre J, 1994, MECH SOLID MAT

[8]

LIN JM, 1992, THESIS TONGJI U SHAN

[9]

Rousselier's G., 1980, P IUTAM S 3 DIM CONS, V1981, P331

[10] Screw dislocations generated from crack tip of self-consistent and self-equilibrated systems of residual stresses: Atomic, meso and micro [J].

Sih, GC ;

Tang, XS .

THEORETICAL AND APPLIED FRACTURE MECHANICS, 2005, 43 (03) :261-307

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