The Design of a Key Expansion Algorithm Based on Dynamic Dislocation Counts

2015 ◽  
Author(s):  
Zhouquan Du ◽  
Qijian Xu ◽  
Jie Zhang ◽  
Xudong Zhong
Keyword(s):  
Dynamic Dislocation

Dynamic dislocation pile-ups

1983 ◽  
Vol 47 (5) ◽  
pp. 707-719 ◽  
Author(s):  
Hilary Ockendon ◽  
J. R. Ockendon
Keyword(s):  
Dynamic Dislocation

First motions from seismic sources

1960 ◽  
Vol 50 (1) ◽  
pp. 117-134 ◽  
Author(s):  
Leon Knopoff ◽  
Freeman Gilbert
Keyword(s):  
Radiation Pattern ◽  
Fault Plane ◽  
Displacement Vector ◽  
Strain Tensor ◽  
Dislocation Model ◽  
Double Couple ◽  
First Motion ◽  
Sudden Release ◽  
Deep Focus ◽  
Dynamic Dislocation

ABSTRACT An application of dynamic dislocation theory gives the elastodynamic radiation resulting from the sudden occurrence of an earthquake due to faulting. The fault plane is visualized as a geometrical discontinuity across which there exists a sudden discontinuity in either one component of the strain tensor or one component of the displacement vector. It is shown that there are eight independent models, if unilateral faulting is assumed; and an argument is presented to demonstrate the likelihood that unilateral faulting does not exist in nature. For bilateral faulting the eight independent models are reduced in number to five. Of these five, two are more likely to occur in nature than the others. One of these, the displacement dislocation model, has a first-motion radiation pattern formally identical with that of a double couple in an unfaulted medium. The second, the shearstrain dislocation model, has a first-motion radiation pattern formally identical with that of an isolated force in an unfaulted medium. The latter type of mechanism may occur in deep-focus earthquakes. Another type of radiation, corresponding to the single couple in an unfaulted medium, results from the sudden release of shear strain in a laminar region.

Dynamic dislocation pile-ups

1983 ◽  
Vol 47 (5) ◽  
pp. 707-719 ◽  
Author(s):  
Hilary Ockendon ◽  
J. R. Ockendon
Keyword(s):  
Dynamic Dislocation

scholarly journals The Scattering of Phonons by Infinitely Long Quantum Dislocations Segments and the Generation of Thermal Transport Anisotropy in a Solid Threaded by Many Parallel Dislocations

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1711
Author(s):  
Fernando Lund ◽  
Bruno Scheihing-Hitschfeld
Keyword(s):  
Elastic Waves ◽  
Thermal Transport ◽  
Dislocation Line ◽  
Canonical Quantization ◽  
Angle Of Incidence ◽  
Coupling Constant ◽  
Line Configuration ◽  
Straight Line ◽  
Quantum Dislocations ◽  
Dynamic Dislocation

A canonical quantization procedure is applied to the interaction of elastic waves—phonons—with infinitely long dislocations that can oscillate about an equilibrium, straight line, configuration. The interaction is implemented through the well-known Peach–Koehler force. For small dislocation excursions away from the equilibrium position, the quantum theory can be solved to all orders in the coupling constant. We study in detail the quantum excitations of the dislocation line and its interactions with phonons. The consequences for the drag on a dislocation caused by the phonon wind are pointed out. We compute the cross-section for phonons incident on the dislocation lines for an arbitrary angle of incidence. The consequences for thermal transport are explored, and we compare our results, involving a dynamic dislocation, with those of Klemens and Carruthers, involving a static dislocation. In our case, the relaxation time is inversely proportional to frequency, rather than directly proportional to frequency. As a consequence, the thermal transport anisotropy generated on a material by the presence of a highly-oriented array of dislocations is considerably more sensitive to the frequency of each propagating mode, and, therefore, to the temperature of the material.

Characterization of Ageing Products in AA6111 Using Dynamic Dislocation-Defect Analysis

2006 ◽  
Vol 519-521 ◽  
pp. 777-782
Author(s):  
Shigeo Saimoto ◽  
S. Subbaiyan ◽  
C. Gabryel
Keyword(s):  
Volume Fraction ◽  
Deformation Mode ◽  
Artificial Ageing ◽  
Defect Analysis ◽  
Dislocation Defect ◽  
The Mean ◽  
Sufficient Strength ◽  
Dynamic Dislocation ◽  
Strength And Ductility

In dynamic dislocation-defect analysis, the thermodynamic deformation-mode signatures are examined as the ageing proceeds. In this method, the activation volume (ν) and the mean slip distance (λ) is simultaneously determined with the flow stress (τ) such that the inverse workhardening slope (1/θ) can be plotted versus b2λ/ν where b is the Burgers vector. The slope of this almost linear locus is directly proportional to the activation distance (d). Calibration with a model alumina-dispersed high conductivity copper reveals that punched-out loops are produced up to failure and is represented by a linear locus from 0.1 to 11 % strain. Artificial ageing of AA6111 at 180°C follows this pattern but the naturally-aged specimen manifest a distinctly different signature which shows a transition as the GP zone-type precipitates are sheared. Furthermore by selecting a suitable tensile-test temperature below 250K, the particle size and volume fraction can be determined if particle shearing does not take place. The optimum size and volume fraction necessary for sufficient strength and ductility can be assessed using this method.

Dynamic dislocation behaviour in the intermetallic compounds NiAl, TiAl and MoSi2

1998 ◽  
Vol 6 (7-8) ◽  
pp. 729-733 ◽  
Author(s):  
U. Messerschmidt ◽  
M. Bartsch ◽  
S. Guder ◽  
D. Häuβler ◽  
R. Haushälter ◽  
...  
Keyword(s):  
Intermetallic Compounds ◽  
Dislocation Behaviour ◽  
Dynamic Dislocation
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