scholarly journals Atomistically enabled nonsingular anisotropic elastic representation of near-core dislocation stress fields inα-iron

2015 ◽  
Vol 91 (18) ◽  
Author(s):  
Dariush Seif ◽  
Giacomo Po ◽  
Matous Mrovec ◽  
Markus Lazar ◽  
Christian Elsässer ◽  
...  
Keyword(s):  
Stress Fields ◽  
Dislocation Stress ◽  
Anisotropic Elastic ◽  
Core Dislocation

Dislocation stress fields in α-Fe

1965 ◽  
Vol 15 (8) ◽  
pp. 595-601 ◽  
Author(s):  
J. Baštecká
Keyword(s):  
Stress Fields ◽  
Dislocation Stress

Three-Dimensional Green’s Functions in Anisotropic Elastic Bimaterials With Imperfect Interfaces

2003 ◽  
Vol 70 (2) ◽  
pp. 180-190 ◽  
Author(s):  
E. Pan
Keyword(s):  
Green's Functions ◽  
Green’S Functions ◽  
Three Dimensional ◽  
Imperfect Interface ◽  
Boundary Integral ◽  
Stress Fields ◽  
Superposition Method ◽  
Interface Conditions ◽  
Complementary Part ◽  
Anisotropic Elastic

In this paper, three-dimensional Green’s functions in anisotropic elastic bimaterials with imperfect interface conditions are derived based on the extended Stroh formalism and the Mindlin’s superposition method. Four different interface models are considered: perfect-bond, smooth-bond, dislocation-like, and force-like. While the first one is for a perfect interface, other three models are for imperfect ones. By introducing certain modified eigenmatrices, it is shown that the bimaterial Green’s functions for the three imperfect interface conditions have mathematically similar concise expressions as those for the perfect-bond interface. That is, the physical-domain bimaterial Green’s functions can be obtained as a sum of a homogeneous full-space Green’s function in an explicit form and a complementary part in terms of simple line-integrals over [0,π] suitable for standard numerical integration. Furthermore, the corresponding two-dimensional bimaterial Green’s functions have been also derived analytically for the three imperfect interface conditions. Based on the bimaterial Green’s functions, the effects of different interface conditions on the displacement and stress fields are discussed. It is shown that only the complementary part of the solution contributes to the difference of the displacement and stress fields due to different interface conditions. Numerical examples are given for the Green’s functions in the bimaterials made of two anisotropic half-spaces. It is observed that different interface conditions can produce substantially different results for some Green’s stress components in the vicinity of the interface, which should be of great interest to the design of interface. Finally, we remark that these bimaterial Green’s functions can be implemented into the boundary integral formulation for the analysis of layered structures where imperfect bond may exist.

Anisotropy migration of self-point defects in dislocation stress fields in BCC Fe and FCC Cu

2007 ◽  
Vol 367-370 ◽  
pp. 316-321 ◽  
Author(s):  
A.B. Sivak ◽  
V.M. Chernov ◽  
N.A. Dubasova ◽  
V.A. Romanov
Keyword(s):  
Point Defects ◽  
Stress Fields ◽  
Dislocation Stress

scholarly journals Displacement and stress fields due to finite faults and opening-mode fractures in an anisotropic elastic half-space

2015 ◽  
Vol 203 (2) ◽  
pp. 1193-1206 ◽  
Author(s):  
E. Pan ◽  
A. Molavi Tabrizi ◽  
A. Sangghaleh ◽  
W. A. Griffith
Keyword(s):  
Half Space ◽  
Elastic Half Space ◽  
Stress Fields ◽  
Opening Mode ◽  
Anisotropic Elastic

Dislocation Locking by Intrinsic Point Defects in Silicon

2001 ◽  
Vol 673 ◽  
Author(s):  
Igor V. Peidous ◽  
Konstantin V. Loiko ◽  
Dale A. Simpson ◽  
Tony La ◽  
William R. Frensley
Keyword(s):  
Point Defects ◽  
Stress Reduction ◽  
Theoretical Calculations ◽  
Elastic Interaction ◽  
Stress Fields ◽  
Intrinsic Point Defects ◽  
Silicon Structures ◽  
External Stresses ◽  
Dislocation Stress ◽  
Dislocation Pileups

ABSTRACTDislocation pileups with abnormally weak inter-dislocation repulsion have been observed in locally oxidized silicon structures. To verify if this could be attributed to elastic interaction of dislocations with intrinsic point defects, distributions of self-interstitials in dislocation stress fields have been studied using theoretical calculations and computer simulations. According to the obtained results, self-interstitials can form atmospheres about dislocations causing dislocation stress reduction and therefore screening of dislocations from interaction with external stresses. This may represent an additional mechanism of dislocation locking in silicon alternative to oxygen pinning.

Dislocation models and seismomagnetic calculations for California 1906 and Alaska 1964 earthquakes

1969 ◽  
Vol 59 (4) ◽  
pp. 1435-1448
Author(s):  
Sabiha Shamsi ◽  
Frank D. Stacey
Keyword(s):  
San Francisco ◽  
Stress Fields ◽  
Maximum Value ◽  
Dislocation Models ◽  
Vertical Displacements ◽  
Dislocation Stress ◽  
Fault Displacement ◽  
Analytical Expressions ◽  
Best Fit ◽  
Fault Length

Abstract For eathquakes occurring on fault planes whose horizontal dimensions are very much greater than the vertical dimensions, the assumption of infinite fault length allows the dislocation stress fields to be expressed by simple analytical equations. This facilitates an important generalization of the dislocation theory of earthquakes, in which the fault displacement is graded to zero at the edges of the fault planes, thus avoiding singularities in the stress fields, which are still represented by straightforward analytical expressions. This development is necessary for realistic calculations of seismomagnetic anomalies, due to the piezomagnetic effect in rocks above the Curie point isotherm. The best fit to geodetic observations on the San Francisco earthquake of 1906 is given by a model in which a horizontal slip of 5m at the surface grades either linearly or sinusoidally to zero at (5 ± 1.5) km depth. Vertical displacements of the Alaskan earthquake of 1964 are represented by a compound dislocation having a vertical slip with a maximum value of 40m at 65m depth, graded to zero at 5km and 125km. Maximum total magnetic field anomalies for these models are respectively 2 gammas and 1 gamma per 10−3 e.m.u. of rock magnetization.

scholarly journals Damage Zone Size Limit During the Crack Propagation

2020 ◽  
Author(s):  
Hamid Hamli Benzahar ◽  
Mohamed Chabaat
Keyword(s):  
Finite Element ◽  
Crack Propagation ◽  
Damage Zone ◽  
Stress Fields ◽  
Mode I ◽  
Zone Size ◽  
Zone Length ◽  
Dislocation Stress ◽  
Rectangular Element

The principal goal of this work is to limit the damage zone length during the crack propagation in brittle materials. This study is based on the determination of stress fields by varying the distance between a semi-infinite crack and a neighboring dislocation. The model suggested is a rectangular element (a dish), having a semi-infinite crack in one of its ends and a dislocation located in the vicinity of a crack-tip, subjected to a tensile stress on mode I. The problem is treated numerically using Finite Element Method.For each distance between the two cracks (semi-infinite crack and dislocation), stress fields are given. On the basis of these stress fields, a limiting damage zone length is obtained.

Dislocation stress fields for dynamic codes using anisotropic elasticity: methodology and analysis

2001 ◽  
Vol 309-310 ◽  
pp. 288-293 ◽  
Author(s):  
Moono Rhee ◽  
James S. Stolken ◽  
Vasily V. Bulatov ◽  
Tomas Diaz de la Rubia ◽  
Hussein M. Zbib ◽  
...  
Keyword(s):  
Anisotropic Elasticity ◽  
Stress Fields ◽  
Dislocation Stress
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