Large-strain deformation and strain partitioning in polyphase rocks: Dislocation creep of olivine–magnesiowüstite aggregates

2006 ◽  
Vol 427 (1-4) ◽  
pp. 115-132 ◽  
Author(s):  
Misha Bystricky ◽  
Florian Heidelbach ◽  
Steve Mackwell
Keyword(s):  
Large Strain ◽  
Dislocation Creep ◽  
Strain Partitioning ◽  
Polyphase Rocks

scholarly journals Ductile Shear Bands in a Naturally Deformed Quartzite

1982 ◽  
Vol 5 (1) ◽  
pp. 1-17 ◽  
Author(s):  
D. Gapais ◽  
S. H. White
Keyword(s):  
Shear Band ◽  
Large Strain ◽  
Shear Bands ◽  
Grain Boundary Sliding ◽  
Dislocation Creep ◽  
Band Structures ◽  
Transmission Electron ◽  
Dynamic Recrystallisation ◽  
Ductile Shear ◽  
Quartz Fabrics

Microscale shear bands are features that often occur oblique to the mylonitic foliation in mylonites. This paper is concerned with such structures within a quartz-mylonite. Geometrical features, microstructures and fabrics associated with shear bands are described. Both optical and transmission electron microscopy have been used. It was observed that the development of shear bands is closely related to (i) the onset of dynamic recrystallisation during deformation, (ii) a change of bulk deformation within the mylonites from relatively homogeneous to inhomogeneous and (iii) a marked softening of the mylonite. Across shear bands, dominant deformation mechanisms change from a dislocation creep type to grain boundary sliding. This induces strong modification of quartz lattice preferred orientations. The asymmetry of quartz fabrics due to shear should generally be favoured by the development of shear band structures. Our results indicate that the production of ductile shear band structures helps to accommodate large strain deformations at low temperatures. Results also indicate that grain and sub-grain sizes are not affected by variations in strain rate.

Small and large strain behaviour of an unsaturated compacted silt

2008 ◽  
Vol 12 (3) ◽  
pp. 203-228 ◽  
Author(s):  
Said Taïbi ◽  
Jean-Marie Fleureau ◽  
Sigit Hadiwardoyo ◽  
Siba Kheirbek-Saoud
Keyword(s):  
Large Strain ◽  
Strain Behaviour

DISLOCATION CREEP IN SUPER--LIGHT α SOLID SOLUTION BASE Mg--6Li--3Zn ALLOY

2010 ◽  
Vol 46 (6) ◽  
pp. 715-722 ◽  
Author(s):  
Furong CAO ◽  
Renguo GUAN ◽  
Hua DING ◽  
Yinglong LI ◽  
Ge ZHOU ◽  
...  
Keyword(s):  
Solid Solution ◽  
Dislocation Creep

STRUCTURE, KINEMATICS, AND STRAIN PARTITIONING OF AN EXHUMED HIGH PRESSURE TERRAIN: THE ROAN WINDOW, NORWAY

2019 ◽  
Author(s):  
Christine E. Newville ◽  
◽  
Christian Teyssier ◽  
Donna L. Whitney ◽  
Hannah J. Blatchford
Keyword(s):  
High Pressure ◽  
Strain Partitioning

Analytical Solutions for Circular Bars Subjected to Large Strain Plastic Torsion

1990 ◽  
Vol 57 (2) ◽  
pp. 298-306 ◽  
Author(s):  
K. W. Neale ◽  
S. C. Shrivastava
Keyword(s):  
Closed Form ◽  
Analytical Solutions ◽  
Large Strain ◽  
Kinematic Hardening ◽  
Flow Theory ◽  
Constitutive Laws ◽  
Isotropic Hardening ◽  
Large Strains ◽  
Inelastic Behavior ◽  
Rate Dependent

The inelastic behavior of solid circular bars twisted to arbitrarily large strains is considered. Various phenomenological constitutive laws currently employed to model finite strain inelastic behavior are shown to lead to closed-form analytical solutions for torsion. These include rate-independent elastic-plastic isotropic hardening J2 flow theory of plasticity, various kinematic hardening models of flow theory, and both hypoelastic and hyperelastic formulations of J2 deformation theory. Certain rate-dependent inelastic laws, including creep and strain-rate sensitivity models, also permit the development of closed-form solutions. The derivation of these solutions is presented as well as numerous applications to a wide variety of time-independent and rate-dependent plastic constitutive laws.

Microstructural Design of an AlMgSi Alloy via ECAP Processing: An Advanced SPD Manufacturing Technique for NC/UFG Materials

2015 ◽  
Vol 1114 ◽  
pp. 143-148
Author(s):  
Nicolae Serban ◽  
Doina Răducanu ◽  
Vasile Danut Cojocaru ◽  
Nicolae Ghiban
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Grain Refinement ◽  
Shape Change ◽  
Large Strain ◽  
Metallographic Analysis ◽  
Cross Sectional ◽  
Ecap Processing ◽  
Microstructural Design ◽  
Almgsi Alloy

Severe plastic deformation (SPD) has received enormous interest over the last two decades as a method capable of producing fully dense and bulk ultra-fine grained (UFG) and nanocrystalline (NC) materials. Significant grain refinement obtained by SPD leads to improvement of mechanical, microstructural and physical properties. Compared to classical deformation processes, the big advantage of SPD manufacturing techniques, represented in particular by equal channel angular pressing (ECAP) is the lack of shape-change deformation and the consequent possibility to impart extremely large strain. In ECAP processing, the workpiece is pressed through a die in which two channels of equal cross-section intersect at an angle of ϕ and an additional angle of ψ define the arc of curvature at the outer point of intersection of the two channels. As a result of pressing, the sample theoretically deforms by simple shear and retains the same cross-sectional area to allow repeated pressings for several cycles. A commercial AlMgSi alloy was investigated in our study. The specimens were processed at room temperature for multiple passes, using three different ECAP dies. All samples (ECAP processed and as-received) were subjected to metallographic analysis and mechanical testing. Several correlations between the main processing parameters and the resulting microstructural aspect and mechanical features for the processed material were established. It was shown that severe plastic deformation by means of ECAP processing can be used in aluminum alloys microstructural design as an advanced tool for grain refinement in order to attain the desired microstructure and mechanical properties.

Long distance plutonic relationships demonstrate 33 million years of strain partitioning along the Denali fault

Terra Nova ◽  
2021 ◽  
Author(s):  
S.P. Regan ◽  
J.A. Benowitz ◽  
T.S. Waldien ◽  
M.E. Holland ◽  
S.M. Roeske ◽  
...  
Keyword(s):  
Strain Partitioning ◽  
Long Distance ◽  
Denali Fault
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