Energy-Based Method for Analyzing the Collapse Characteristics of Silt Subjected to Changes of Principal Stress Orientation

2011 ◽  
Vol 39 (5) ◽  
pp. 103391
Author(s):  
M. R. Mitchell ◽  
R. E. Link ◽  
Jun Yan ◽  
Yang Shen ◽  
Guofa Huang ◽  
...  
Keyword(s):  
Principal Stress ◽  
Stress Orientation ◽  
Collapse Characteristics

Nonuniform Stress Field Determination Based on Deformation Measurement

2021 ◽  
pp. 1-26
Author(s):  
Cheng Liu
Keyword(s):  
Principal Stress ◽  
Deformation Gradient ◽  
Deformation Measurement ◽  
Cauchy Stress ◽  
Kirchhoff Stress ◽  
Nonuniform Deformation ◽  
Principal Stretch ◽  
Stress Orientation ◽  
Lagrangian Strain ◽  
Stretch Orientation

Abstract We demonstrate a technique that, under certain circumstances, will determine stresses associated with a nonuniform deformation field without knowing the detailed constitutive behavior of the deforming material. This technique is based on (1) a detailed deformation measurement of a domain and (2) the observation that for isotropic materials, the strain and the stress, which form the so-called work-conjugate pair, are co-axial, or their eigenvectors share the same direction. The particular measures for strain and stress considered are the Lagrangian strain and the second Piola-Kirchhoff stress. The deformation measurement provides the field of the principal stretch orientation θλ and since the Lagrangian strain and the second Piola-Kirchhoff stress are co-axial, the principal stress orientation θs of the second Piola-Kirchhoff stress is determined. The Cauchy stress is related to the second Piola-Kirchhoff stress through the deformation gradient tensor, which can be measured experimentally. We then show that the principal stress orientation θσ of the Cauchy stress is the sum of the principal stretch orientation θλ and the local rigid-body rotation θq, which is determinable by the deformation gradient through polar decomposition. With the principal stress orientation θσ known, the equation of equilibrium, now in terms of the two principal stresses σ1 and σ2, and θσ, can be solved numerically with appropriate traction boundary conditions. The technique is then applied to the experimental case of nonuniform deformation of a PVC sheet with a circular hole and subject to tension. Limitations and restrictions of the technique and possible extensions will be discussed.

Revisit on the analytic formulations of principal stress orientation in fracture mechanics

2020 ◽  
Author(s):  
Arjun Ajit Kottara ◽  
Govind Padmanabhan ◽  
M. Maneesh Kumar ◽  
K. Rohit ◽  
M.P. Hariprasad
Keyword(s):  
Fracture Mechanics ◽  
Principal Stress ◽  
Stress Orientation

The effect of principal stress orientation on tunnel stability

2015 ◽  
Vol 49 ◽  
pp. 279-286 ◽  
Author(s):  
Zheming Zhu ◽  
Yuanxin Li ◽  
Jun Xie ◽  
Bang Liu
Keyword(s):  
Principal Stress ◽  
Tunnel Stability ◽  
Stress Orientation

Some influences of stratigraphy and structure on reservoir stress orientation

Geophysics ◽  
1994 ◽  
Vol 59 (6) ◽  
pp. 954-962 ◽  
Author(s):  
Michael S. Bruno ◽  
Don F. Winterstein
Keyword(s):  
Principal Stress ◽  
Compressive Stress ◽  
Horizontal Stress ◽  
Oil Fields ◽  
Fold Axis ◽  
Principal Stresses ◽  
Stress Orientation ◽  
Stress Direction ◽  
Well Pattern ◽  
Maximum Horizontal Stress

The azimuth of maximum horizontal stress in a reservoir can vary significantly with depth and with position on a subsurface structure. We present and discuss evidence from field data for such variation and demonstrate both analytically and with finite‐element modeling how such changes might take place. Under boundary conditions of uniform far‐field displacement, changes in stratigraphic layering can reorient the principal stress direction if the formation is intrinsically anisotropic. If the formation stiffness is lower perpendicular to bedding than parallel to bedding (as is often the case in layered geologic media), an increase in dip will reduce the component of compressive stress in the dip azimuth direction. Folds can reorient principal stresses because flexural strain varies with depth and position. Compressive stress perpendicular to a fold axis increases with depth at the crest of an anticline and decreases with depth at the limb. When the regional stress anisotropy is weak, this change in stress magnitude can reorient the local principal stress directions. Numerical simulations of such effects gave results consistent with changes in stress orientation at the Cymric and Lost Hills oil fields in California as observed via shear‐wave polarization analyses and tiltmeter surveys of hydraulic fracturing. Knowledge of such variation of stress direction with depth and structural position is critical for drilling, completions, hydraulic fracture, and well pattern designs.

Stress orientation, pore pressure and least principal stress in the Norwegian sector of the North Sea

2001 ◽  
Vol 7 (2) ◽  
pp. 173-180 ◽  
Author(s):  
Balz Grollimund ◽  
Mark D. Zoback ◽  
David J. Wiprut ◽  
Linn Arnesen
Keyword(s):  
Pore Pressure ◽  
Principal Stress ◽  
North Sea ◽  
The North ◽  
Stress Orientation ◽  
The North Sea
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