Modeling and Numerical Simulations of Microdiffraction from Deformed Crystals

2002 ◽  
Vol 731 ◽  
Author(s):  
R.I. Barabash ◽  
G.E. Ice ◽  
F.J. Walker
Keyword(s):  
Plastic Deformation ◽  
Three Dimensions ◽  
Alternative Methods ◽  
Deformation Tensor ◽  
Polycrystalline Materials ◽  
Laue Pattern ◽  
Stress Strain ◽  
Crystalline Materials ◽  
Comparable Method ◽  
Tensor Distributions

AbstractBrilliant synchrotron microprobes offer new opportunities for the analysis of stress/strain and deformation distributions in crystalline materials. Polychromatic x-ray microdiffraction is emerging as a particularly important tool because it allows for local crystal-structure measurements in highly deformed or polycrystalline materials where sample rotations complicate alternative methods; a complete Laue pattern is generated in each volume element intercepted by the probe beam. Although a straightforward approach to the measurement of stress/strain fields through white-beam Laue microdiffraction has been demonstrated, a comparable method for determining the plastic-deformation tensor has not been established. Here we report on modeling efforts that can guide automated fitting of plastic-deformation-tensor distributions in three dimensions.

Application of the 3D X-Ray Crystal Microscope to Study Mesoscale Structure of Materials

2003 ◽  
Vol 779 ◽  
Author(s):  
Gene E. Ice ◽  
Wenjun Liu ◽  
Bennett C. Larson ◽  
Fredrick J. Walker
Keyword(s):  
Plastic Deformation ◽  
Plastic Strain ◽  
Three Dimensions ◽  
Polycrystalline Materials ◽  
Crystalline Orientation ◽  
Materials Properties ◽  
X Ray ◽  
Mesoscale Structure ◽  
Elastic And Plastic Deformation ◽  
Strain Tensors

AbstractThe 3D x-ray crystal microscope is an emerging tool for the study of mesoscale structure in polycrystalline materials. With this nondestructive device, local crystalline orientation, phase, elastic and plastic strain tensors can be measured with submicron spatial resolution in three dimensions. A key step in analyzing the Laue patterns from the 3D microscope is indexing the reflections, which determines the orientation of the sub-grain. With current algorithms, the angles between pairs, triplets and quadruplets of reflections are compared to theoretical angles to make guesses as to the reflection indices. The ability to index a pattern can however be compromised by both elastic and plastic deformation of a grain; elastic deformation changes the angles between reflections and plastic deformation increases the uncertainty in the centroid of each reflection. Here we report on the use of an indexing algorithm that simultaneously fits all peaks from a subgrain. This algorithm is more robust than previous methods and allows for indexing of deformed or strained grains. Some applications to studies of mesoscale materials properties are described.

Modeling of Inelastic Deformation of f.c.c, Single- and Polycrystalline Materials with Low Stacking Fault Energies

1998 ◽  
Vol 538 ◽  
Author(s):  
A. Staroselsky ◽  
L. Anand
Keyword(s):  
Plastic Deformation ◽  
Single Crystal ◽  
Polycrystalline Materials ◽  
Type Model ◽  
Finite Element Program ◽  
Crystalline Materials ◽  
Element Program ◽  
Structural Levels ◽  
Stacking Fault Energies ◽  
Good Agreement

AbstractA new rate-independent constitutive model for plastic deformation of crystalline materials deforming by slip and twinning has been formulated, and implemented in a finite-element program. We have simulated three different structural levels by choosing representative volume elements (RVEs) as (i) a small part of a single crystal for the analysis of the heterogeneity of plastic deformation in single crystals, (ii) a whole single crystal for polycrystal simulations, and (iii) a group of crystals for a Taylor-type model of polycrystals. We show that the predictions for the texture and stress-strain response from the model are in reasonably good agreement with experiments in plane-strain compression for a different single crystal and polycrystalline f.c.c, materials.

Effect of Residual Stress or Plastic Deformation History on Fatigue Life Simulation of Pipeline Dents

2018 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Rick Wang
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Strain History ◽  
Deformation History ◽  
Stress Strain ◽  
Element Analysis ◽  
Fea Model

Mechanical dents often occur in transmission pipelines, and are recognized as one of major threats to pipeline integrity because of the potential fatigue failure due to cyclic pressures. With matured in-line-inspection (ILI) technology, mechanical dents can be identified from the ILI runs. Based on ILI measured dent profiles, finite element analysis (FEA) is commonly used to simulate stresses and strains in a dent, and to predict fatigue life of the dented pipeline. However, the dent profile defined by ILI data is a purely geometric shape without residual stresses nor plastic deformation history, and is different from its actual dent that contains residual stresses/strains due to dent creation and re-rounding. As a result, the FEA results of an ILI dent may not represent those of the actual dent, and may lead to inaccurate or incorrect results. To investigate the effect of residual stress or plastic deformation history on mechanics responses and fatigue life of an actual dent, three dent models are considered in this paper: (a) a true dent with residual stresses and dent formation history, (b) a purely geometric dent having the true dent profile with all stress/strain history removed from it, and (c) a purely geometric dent having an ILI defined dent profile with all stress/strain history removed from it. Using a three-dimensional FEA model, those three dents are simulated in the elastic-plastic conditions. The FEA results showed that the two geometric dents determine significantly different stresses and strains in comparison to those in the true dent, and overpredict the fatigue life or burst pressure of the true dent. On this basis, suggestions are made on how to use the ILI data to predict the dent fatigue life.

Influence of Severe Plastic Deformation on the PLC Effect and Mechanical Properties in Al 5XXX Alloy

2006 ◽  
Vol 114 ◽  
pp. 171-176 ◽  
Author(s):  
Joanna Zdunek ◽  
Pawel Widlicki ◽  
Halina Garbacz ◽  
Jaroslaw Mizera ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Severe Plastic Deformation ◽  
True Strain ◽  
Tensile Tests ◽  
Size Reduction ◽  
Hydrostatic Extrusion ◽  
Stress Strain ◽  
Chatelier Effect

In this work, Al-Mg-Mn-Si alloy (5483) in the as-received and severe plastically deformed states was used. Plastic deformation was carried out by hydrostatic extrusion, and three different true strain values were applied 1.4, 2.8 and 3.8. All specimens were subjected to tensile tests and microhardness measurements. The investigated material revealed an instability during plastic deformation in the form of serration on the stress-strain curves, the so called Portevin-Le Chatelier effect It was shown that grain size reduction effected the character of the instability.

Stages of plastic deformation of polycrystalline materials

2017 ◽  
pp. 1-49 ◽  
Author(s):  
A. M. Glezer ◽  
E. V. Kozlov ◽  
N. A. Koneva ◽  
N. A. Popova ◽  
I. A. Kurzina
Keyword(s):  
Plastic Deformation ◽  
Polycrystalline Materials

scholarly journals Stress strain state of elastic plate with elliptical cut-out

2020 ◽  
pp. 3-8
Author(s):  
E.E. Deryugin ◽  
Keyword(s):  
Plastic Deformation ◽  
Stress Concentration ◽  
Driving Force ◽  
Strain State ◽  
Mechanical State ◽  
Concentration Coefficient ◽  
Stress Strain ◽  
Crack Driving Force ◽  
Stress Strain State ◽  
Stress Concentration Coefficient

The article considers a crack in the form of a narrow cut with a certain cfn at the cut out in an unbounded plate. The characteristics of the mechanical state of this system under uniaxial loading are determined: the stress concentration coefficient, the crack-driving force, and the energy of a solid with a crack. The elastic energy expenditure during crack propagation is determined. The general regularities of the mechanical state of a solid with a crack, not necessary having the form of an ellipse, are revealed. An important parameter of a crack is the curvature at the tip. It is shown that the Griffiths crack does not actually have a singularity at the tip. The stress strain state of the plate with an elliptical crack is identical to the same of the plate with a focus of homogeneous plastic deformation.

A Theory of Elastic, Plastic, and Creep Deformations of an Initially Isotropic Material Showing Anisotropic Strain-Hardening, Creep Recovery, and Secondary Creep

1958 ◽  
Vol 25 (4) ◽  
pp. 529-536
Author(s):  
J. F. Besseling
Keyword(s):  
Plastic Deformation ◽  
Energy Dissipation ◽  
Strain Hardening ◽  
Isotropic Material ◽  
Creep Recovery ◽  
Secondary Creep ◽  
Stress Strain ◽  
Microscopic Scale ◽  
Anisotropic Strain ◽  
Creep Deformations

Abstract Stress-strain relations are given for an initially isotropic material, which is macroscopically homogeneous, but inhomogeneous on a microscopic scale. An element of volume is considered to be composed of various portions, which can be represented by subelements showing secondary creep and isotropic work-hardening in plastic deformation. If the condition is imposed that all subelements of an element of volume are subjected to the same total strain, it is demonstrated that the inelastic stress-strain relations of the material show anisotropic strain-hardening, creep recovery, and primary and secondary creep due to the nonuniform energy dissipation in deformation of the sub-elements. Only quasi-static deformations under isothermal conditions are considered. The theory is restricted to small total strains.

Recent advances in structures and applications of coordination polymers based on cyclohexanepolycarboxylate ligands

2022 ◽  
Author(s):  
Yong-Cong Ou ◽  
Ri-Ming Zhong ◽  
Jian-Zhong Wu
Keyword(s):  
Coordination Polymers ◽  
Organic Ligands ◽  
Three Dimensions ◽  
Crystalline Materials ◽  
Recent Advances ◽  
Coordination Bonds

Coordination polymers (CPs) are emerging crystalline materials constructed by metal entities and organic ligands through coordination bonds, containing infinite coordination units in one, two, or three dimensions. Here an overview...

Some Properties of a Mechanical Model of Plasticity

1948 ◽  
Vol 15 (3) ◽  
pp. 222-225
Author(s):  
H. F. Bohnenblust ◽  
Pol Duwez
Keyword(s):  
Plastic Deformation ◽  
Potential Energy ◽  
Work Hardening ◽  
Mechanical Model ◽  
Strain Curve ◽  
Hysteresis Curve ◽  
Plastic Range ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Mechanical Models

Abstract Various mechanical models explaining the plastic deformation of metals have been proposed. One of the present authors has shown that in some cases an analytical expression for the stress-strain curve and the hysteresis curve of a metal in the plastic range can be deduced from such a model. The present investigation is a further analysis of the model leading to the computation of the change in potential energy of the metal due to work-hardening.

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