The interaction between two coplanar dislocation-type cracks

1966 ◽  
Vol 292 (1428) ◽  
pp. 134-151 ◽  
Keyword(s):  
Cleavage Fracture ◽  
Interaction Effects ◽  
Crystalline Solids ◽  
Dislocation Type ◽  
Deformation Processes ◽  
Shaped Crack ◽  
Complete Fracture ◽  
The Stability

When crystalline solids exhibit cleavage fracture, the associated deformation processes produce wedge shaped microcracks and the criteria for their stability are of paramount importance when discussing the conditions for complete fracture of a solid. Previously, consideration has been given to the behaviour of an isolated wedge shaped crack, but little attention has been given to problems involving distributions of such cracks. The present paper examines the stability of two coplanar wedge shaped cracks, and demonstrates under what conditions interaction effects are important.

The interaction between dislocation-type cracks II. The infinite periodic sequence of coplanar dislocation-type cracks

1966 ◽  
Vol 295 (1443) ◽  
pp. 421-428 ◽  
Keyword(s):  
Single Crystals ◽  
Magnesium Oxide ◽  
Periodic Sequence ◽  
Experimental Results ◽  
Continuous Distributions ◽  
Dislocation Type ◽  
Complete Fracture ◽  
The Stability

In a previous paper the interaction between two coplanar dislocation-type cracks was studied, the crack openings being described by continuous distributions of dislocations. A similar approach is used here to examine the stability of an infinite periodic sequence of coplanar dislocation-type cracks, each dislocation being such that its associated extra material is pointing in the same direction. Primary consideration is given to the criterion for the cracks to join up thereby causing complete fracture of the solid, and the characteristics of the model are applied to a very brief discussion of some experimental results on the deformation of magnesium oxide single crystals.

Predictive estimates of subsidence of the earth’s surface during the development of the Yamburgskoye oil and gas condensate field

2021 ◽  
pp. 9-22
Author(s):  
Yu. V. Vasiliev ◽  
M. S. Mimeev ◽  
D. A. Misyurev
Keyword(s):  
Oil And Gas ◽  
Active Faults ◽  
Physical And Mechanical Properties ◽  
Deformation Model ◽  
Reservoir Pressure ◽  
Gas Reservoirs ◽  
Field Development ◽  
Geodynamic Processes ◽  
Deformation Processes ◽  
The Stability

The production of hydrocarbons is associated with a change in the physical and mechanical properties of oil and gas reservoirs under the influence of rock and reservoir pressures. Deformation of the reservoir due to a drop in reservoir pressure leads to the formation of various natural and man-made geodynamic and geomechanical phenomena, one of which is the formation of a subsidence trough of the earth's surface, which leads to a violation of the stability of field technological objects.In order to ensure geodynamic safety, a set of works is used, which includes analysis of geological and field indicators and geological and tectonic models of the field, interpretation of aerospace photographs, identification of active faults, construction of a predictive model of subsidence of the earth's surface of the field with identification of zones of geodynamic risk.This work was carried out to assess the predicted parameters of rock displacement processes during field development; even insignificant disturbances in the operation of technological equipment caused by deformation processes can cause significant damage.Prediction of rock displacements is possible only on the basis of a reservoir deformation model that adequately reflects the geomechanical and geodynamic processes occurring in the subsoil. The article presents a model of reservoir deformation with a drop in reservoir pressure, describes its numerical implementation, and performs calculations of schemes for typical development conditions.

The interaction between dislocation-type cracks III. Infinite periodic sequences of noncoplanar cracks

1966 ◽  
Vol 295 (1443) ◽  
pp. 429-439
Keyword(s):  
Plane Strain ◽  
Singular Integral Equations ◽  
Periodic Sequence ◽  
Periodic Sequences ◽  
Plane Strain Tension ◽  
Dislocation Type ◽  
The Stability ◽  
Different Characteristics ◽  
Strain Model

Earlier papers in this series have discussed the interaction between two coplanar dislocation-type cracks and between coplanar cracks that form an infinite periodic sequence, the stability criteria being determined. This paper examines the stability of an infinite periodic sequence of noncoplanar dislocation-type cracks, particular consideration being given to the determination of the complete fracture criterion. Unlike the situation that exists for coplanar dislocation-type cracks, some aspects of the results are radically different depending on whether the mode of deformation is anti-plane strain, plane strain shear, or plane strain tension, and the different characteristics of the three models are emphasized. With the anti-plane strain model exact solutions can be obtained, but with both plane strain shear and plane strain tension models, the governing singular integral equations can only be solved when the cracks are widely spaced.

Enhancing Sensitivity Diagnostics for Qualitative Comparative Analysis: A Combinatorial Approach

2016 ◽  
Vol 24 (1) ◽  
pp. 104-120 ◽  
Author(s):  
Alrik Thiem ◽  
Reto Spöhel ◽  
Adrian Duşa
Keyword(s):  
Comparative Analysis ◽  
Data Quality ◽  
Qualitative Comparative Analysis ◽  
Interaction Effects ◽  
Combinatorial Approach ◽  
Methodological Research ◽  
The Stability ◽  
Parameter Values

Sensitivity diagnostics has recently been put high on the agenda of methodological research into Qualitative Comparative Analysis (QCA). Existing studies in this area rely on the technique of exhaustive enumeration, and the majority of works examine the reactivity of QCA either only to alterations in discretionary parameter values or only to data quality. In this article, we introduce the technique of combinatorial computation for evaluating the interaction effects between two problems afflicting data quality and two discretionary parameters on the stability of QCA reference solutions. In this connection, we challenge a hitherto unstated assumption intrinsic to exhaustive enumeration, show that combinatorial computation permits the formulation of general laws of sensitivity in QCA, and demonstrate that our technique is most efficient.

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