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| DOI | 10.1016/j.tecto.2019.228242 |
| 3D modelling of the effect of thermal-elastic stress on grain-boundary opening in quartz grain aggregates | |
| Raghami E.; Schrank C.; Kruhl J.H. | |
| 发表日期 | 2020 |
| ISSN | 00401951 |
| 卷号 | 774 |
| 英文摘要 | During the exhumation of rocks and the associated temperature and pressure decrease, the anisotropic thermoelastic properties of minerals lead to internal stresses on the grain scale, which in turn cause fracturing and opening of grain and phase boundaries. To gain deeper insight into the onset of grain-boundary cracking and the subsequent evolution of grain-boundary fracture networks after crack initiation, 3D grain-scale numerical modelling has been performed. In detail, the fracturing and opening of quartz grain boundaries during exhumation of quartzite with millimeter-scale grains and randomly oriented crystallographic axes, accompanied by cooling from 300 to 25 °C and decompression from 300 to 22 MPa, have been modelled with contact mechanics and the finite-element method. Model grains have an anisotropic linear-elastic rheology and an anisotropic thermal-expansion tensor. Grain boundaries are modelled as contact surfaces with a non-linear strain-softening rheology in tension and a Mohr-Coulomb rheology in shear. Grain-boundary fractures nucleate at grain vertices and triple lines, in agreement with observations in nature and experiment. Comparison with grain-boundary opening data from natural quartzite indicates that the tensile yield strength (σy) of quartz grain boundaries has an upper bound of 75 MPa, with best-fit results for σy = 25 MPa. Moreover, the best-fit model implies that quartz grain-boundary opening initiates after a temperature and pressure decrease of around 80 °C and 80 MPa. © 2019 Elsevier B.V. |
| 关键词 | anisotropic thermoelastic propertiesgrain boundaryinternal stresstensile yield strengththermal cracking |
| 英文关键词 | 3D modeling; Anisotropy; Cracks; Deformation; Elasticity; Fracture; Metamorphic rocks; Quartz; Residual stresses; Tensile strength; Thermal expansion; Thermoelasticity; Yield stress; Anisotropic thermal expansion; Crystallographic axes; Grain boundary cracking; Grain boundary fracture; Temperature and pressures; Tensile yield strength; Thermal cracking; Thermoelastic properties; Grain boundaries; aggregate; anisotropy; grain boundary; quartz; stress analysis; tensile strength; thermoelasticity; three-dimensional modeling |
| 语种 | 英语 |
| 来源期刊 | Tectonophysics
 |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://gcip.llas.ac.cn/handle/2XKMVOVA/207855 |
| 作者单位 | Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität, Munich, 80333, Germany; School of Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, 4001, Australia |
| 推荐引用方式 GB/T 7714 | Raghami E.,Schrank C.,Kruhl J.H.. 3D modelling of the effect of thermal-elastic stress on grain-boundary opening in quartz grain aggregates[J],2020,774. |
| APA | Raghami E.,Schrank C.,&Kruhl J.H..(2020).3D modelling of the effect of thermal-elastic stress on grain-boundary opening in quartz grain aggregates.Tectonophysics,774. |
| MLA | Raghami E.,et al."3D modelling of the effect of thermal-elastic stress on grain-boundary opening in quartz grain aggregates".Tectonophysics 774(2020). |
| 条目包含的文件 | 条目无相关文件。 | |||||
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