scholarly journals Modeling of fault gouges with Cosserat Continuum Mechanics: Influence of thermal pressurization and chemical decomposition as coseismic weakening mechanisms

2012 ◽  
Vol 38 ◽  
pp. 254-264 ◽  
Author(s):  
Emmanuil Veveakis ◽  
Jean Sulem ◽  
Ioannis Stefanou
Keyword(s):  
Continuum Mechanics ◽  
Cosserat Continuum ◽  
Chemical Decomposition ◽  
Thermal Pressurization ◽  
Fault Gouges

scholarly journals Research on the deformation of a confined aquifer based on Cosserat continuum mechanics

2015 ◽  
Vol 372 ◽  
pp. 399-401
Author(s):  
Y. S. Xu ◽  
N. Zhang ◽  
Y. Yuan ◽  
S. L. Shen
Keyword(s):  
Shear Stress ◽  
Continuum Mechanics ◽  
Land Subsidence ◽  
Cosserat Continuum ◽  
Shear Stresses ◽  
Asymmetric Distribution ◽  
Soil Deformation ◽  
Main Factors ◽  
Sandy Aquifers ◽  
Aquifer Unit

Abstract. Recent monitoring of land subsidence and soil deformation indicates a new phenomenon where excessive and continuous deformation occurs in the sandy aquifers in Shanghai and the Su-Xi-Chang region of China. It is hard to explain factors contributing to this phenomenon with traditional Cauchy continuum mechanics in which low normal stress in the ground could not cause such large deformation. Steep hydraulic gradient would be formed in the aquifer if groundwater is pumped from densely distributed wells, and shear stresses would develop then. Accumulated shear stress could then lead to deformation of the aquifer or even land subsidence. Accumulated shear stress due to the drawdown of groundwater level is one of the main factors that contribute to deformation within an aquifer. Traditional Cauchy continuum mechanics cannot consider this shear stress because of the hypothesis of equal shear stress in the aquifer unit. Cosserat continuum mechanics can be applied to analyse the mechanism of aquifer deformation controlled by accumulated shear stress by considering the scale effect and the asymmetric distribution of shear stress in the aquifer unit.

A First Course in Continuum Mechanics

2001 ◽  
Author(s):  
Oscar Gonzalez ◽  
Andrew M. Stuart
Keyword(s):  
Continuum Mechanics

Analysis of shear bands in slow granular flows using a frictional Cosserat model

2000 ◽  
Vol 627 ◽  
Author(s):  
Prabhu R. Nott ◽  
K. Kesava Rao ◽  
L. Srinivasa Mohan
Keyword(s):  
Scaling Laws ◽  
Shear Bands ◽  
Shear Layers ◽  
Theoretical Description ◽  
Field Variable ◽  
Cosserat Continuum ◽  
Momentum Balance ◽  
Rigid Plastic ◽  
Independent Field ◽  
Cosserat Model

ABSTRACTThe slow flow of granular materials is often marked by the existence of narrow shear layers, adjacent to large regions that suffer little or no deformation. This behaviour, in the regime where shear stress is generated primarily by the frictional interactions between grains, has so far eluded theoretical description. In this paper, we present a rigid-plastic frictional Cosserat model that captures thin shear layers by incorporating a microscopic length scale. We treat the granular medium as a Cosserat continuum, which allows the existence of localised couple stresses and, therefore, the possibility of an asymmetric stress tensor. In addition, the local rotation is an independent field variable and is not necessarily equal to the vorticity. The angular momentum balance, which is implicitly satisfied for a classical continuum, must now be solved in conjunction with the linear momentum balances. We extend the critical state model, used in soil plasticity, for a Cosserat continuum and obtain predictions for flow in plane and cylindrical Couette devices. The velocity profile predicted by our model is in qualitative agreement with available experimental data. In addition, our model can predict scaling laws for the shear layer thickness as a function of the Couette gap, which must be verified in future experiments. Most significantly, our model can determine the velocity field in viscometric flows, which classical plasticity-based model cannot.

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