Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/88626
Title: Influence of grain size heterogeneity on strength and microcracking behavior of crystalline rocks
Authors: Peng, Jun
Wong, Louis Ngai Yuen
Teh, Cee Ing
Keywords: Grain Boundary Microcrack
Heterogeneity
Issue Date: 2017
Source: Peng, J., Wong, L. N. Y., & Teh, C. I. (2017). Influence of grain size heterogeneity on strength and microcracking behavior of crystalline rocks. Journal of Geophysical Research: Solid Earth, 122(2), 1054-1073.
Series/Report no.: Journal of Geophysical Research: Solid Earth
Abstract: This study numerically investigates the influence of material heterogeneity on the strength and deformation behavior and the associated microcracking process of a felsic crystalline rock using a grain‐based modeling approach in two‐dimensional Particle Flow Code. By using a heterogeneity index defined in this study, the heterogeneity induced by variation of grain size distribution can be explicitly incorporated into the numerical specimen models quantitatively. Under compressive loading, the peak strength and the elastic modulus are found to increase as the numerical model gradually changes from heterogeneous to homogeneous, i.e., a decrease of heterogeneity index. Meanwhile, the number of grain boundary tensile cracks gradually decreases and the number of intragrain cracks increases at the moment of failure. However, the total number of generated microcracks seems not to be significantly influenced by heterogeneity. The orientation of grain boundary microcracks is mainly controlled by the geometry of assembled grain structure of the numerical specimen model, while the orientation of intragrain microcracks is to a large degree influenced by the confinement. In addition, the development of intragrain cracks (both tensile and shear) is much more favored in quartz than in other minerals. Under direct tensile loading, heterogeneity is found to have no significant influence on the simulated stress‐strain responses and rock strength. Only grain boundary tensile cracks are generated when the numerical models are loaded in direct tension, and the position of generated macroscopic fracture developed upon failure of the specimen is largely affected by heterogeneity.
URI: https://hdl.handle.net/10356/88626
http://hdl.handle.net/10220/44679
ISSN: 2169-9313
DOI: http://dx.doi.org/10.1002/2016JB013469
Rights: © 2017 American Geophysical Union (AGU). This paper was published in Journal of Geophysical Research : Solid Earth and is made available as an electronic reprint (preprint) with permission of American Geophysical Union (AGU). The published version is available at: [http://dx.doi.org/10.1002/2016JB013469]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.
Fulltext Permission: open
Fulltext Availability: With Fulltext
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