Stored Energy and Recrystallization Process

2007 ◽  
Vol 539-543 ◽  
pp. 3335-3340 ◽  
Author(s):  
Andrzej Baczmanski ◽  
Krzysztof Wierzbanowski ◽  
Abdelilah Benmarouane ◽  
Alain Lodini ◽  
Paul Lipiński ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Residual Stresses ◽  
Elastic Energy ◽  
Crucial Role ◽  
Driving Force ◽  
Recrystallization Process ◽  
Stored Energy ◽  
Grain Interaction ◽  
Deformation Models

Stored energy plays a crucial role in recrystallization process. One can distinguish two contributions to this energy. The first one is the elastic energy, connected with residual stresses, i.e., with grain-grain interaction. Another part of the stored energy is due to dislocation density, which is mainly localized inside grains. The latter one is considered as a main driving force of recrystallization. However, the stored energy connected with residual stresses can also have some influence on this process. Both types of energy can be determined experimentally and predicted by deformation models. Taking into account both types of the stored energy, some features of recrystallization textures can be explained.

Stored Energy of Plastic and Elastic Origin and Recrystallization

2008 ◽  
Vol 571-572 ◽  
pp. 143-148
Author(s):  
Krzysztof Wierzbanowski ◽  
Andrzej Baczmanski ◽  
Jacek Tarasiuk ◽  
Paul Lipiński ◽  
Alain Lodini
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Dislocation Density ◽  
Stress Field ◽  
Driving Force ◽  
Recrystallization Process ◽  
Stored Energy ◽  
Residual Stress Field ◽  
Orientation Distributions ◽  
Deformation Models

Stored energy is generally considered as a main driving force of recrystallization process. After plastic deformation a high dislocation density and residual stress field remain in a material. Both quantities are at the origin of the stored energy and we call them as the “plastic” and “elastic” parts of this energy. Their orientation distributions can be determined using diffraction and deformation models. Both components of the stored energy are studied in the present work. Their distributions and characteristics are studied for f.c.c. and b.c.c. materials.

Residual stresses, dislocation density and recrystallization process

2007 ◽  
Vol 15 (3) ◽  
pp. 281-287 ◽  
Author(s):  
A. Baczmanski ◽  
K. Wierzbanowski ◽  
P. Lipinski ◽  
B. Bacroix ◽  
A. Lodini
Keyword(s):  
Dislocation Density ◽  
Residual Stresses ◽  
Recrystallization Process

Adventism, Apocalyptic, and the Cause of Liberty

1994 ◽  
Vol 63 (2) ◽  
pp. 235-249
Author(s):  
Douglas Morgan
Keyword(s):  
Nineteenth Century ◽  
Crucial Role ◽  
Driving Force ◽  
Late Nineteenth Century ◽  
The Past ◽  
Conservative Protestantism ◽  
Late Nineteenth

“I have felt like working three times as hard as ever since I came to understand that my Lord was coming back again,” reported revivalist Dwight L. Moody, the most prominent of nineteenth-century premillennialists. Moody's testimony to the motivating power of premillennialism points to the crucial role of that eschatology in conservative Protestantism since the late nineteenth century—a role delineated by several studies within the past twenty-five years. As a comprehensive interpretation of history which gives meaning and pattern to past, present, and future, and a role for the believer in the outworking of the divine program, premillennialism has been a driving force in the fundamentalistand evangelical movements.

Maximising Soft Power: the Role of Digital Diplomacy in Building Trust with Nation-Branding

2021 ◽  
Vol 1 (2) ◽  
pp. 1-19
Author(s):  
Jess Gosling
Keyword(s):  
Crucial Role ◽  
Soft Power ◽  
Driving Force ◽  
Public Diplomacy ◽  
Essential Role ◽  
Nation Branding ◽  
Building Trust ◽  
The Creation ◽  
Digital Diplomacy

Perceptions of attractiveness and trustworthiness impact the prosperity and influence of countries. A country's soft power is not guaranteed. Countries have their brands, an image shaped by the behaviour of governments, by what they do and say, whom they associate with, and how they conduct themselves on the global stage. Increasingly, digital diplomacy plays a crucial role in the creation and application of soft power. This paper argues that digital diplomacy is increasingly vital in the articulation of soft power. Digital diplomacy is a new way of conducting public diplomacy, offering new and unparalleled ways of building trust with previously disengaged audiences. Soft power is now the driving force behind reputation and influence on the global stage, where increasingly digital diplomacy plays an essential role.

scholarly journals Short fatigue crack growth in welded joints described by the effective cyclic J-integral

2018 ◽  
Vol 165 ◽  
pp. 09002
Author(s):  
Désiré Tchoffo Ngoula ◽  
Michael Vormwald
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Fatigue Crack Growth ◽  
Residual Stresses ◽  
Crack Growth ◽  
Welded Joints ◽  
Driving Force ◽  
J Integral ◽  
Crack Driving Force ◽  
Short Fatigue Crack

The purpose of the present contribution is to predict the fatigue life of welded joints by using the effective cyclic J-integral as crack driving force. The plasticity induced crack closure effects and the effects of welding residual stresses are taken into consideration. Here, the fatigue life is regarded as period of short fatigue crack growth. The node release technique is used to perform finite element based crack growth analyses. For fatigue lives calculations, the effective cyclic J-integral is employed in a relation similar to the Paris (crack growth) equation. For this purpose, a specific code was written for the determination of the effective cyclic J-integral for various lifetime relevant crack lengths. The effects of welding residual stresses on the crack driving force and the calculated fatigue lives are investigated. Results reveal that the influence of residual stresses can be neglected only for large load amplitudes. Finally, the predicted fatigue lives are compared with experimental data: a good accordance between both results is achieved.

The pointwise Eshelby force on the interface between a transformed inclusion and its surrounding matrix

2016 ◽  
Vol 23 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Steven D Gavazza ◽  
David M Barnett
Keyword(s):  
Elastic Energy ◽  
Driving Force ◽  
Energy Momentum Tensor ◽  
Normal Component ◽  
Strain Tensor ◽  
Transformation Strain ◽  
Momentum Tensor ◽  
Surrounding Matrix ◽  
Personal Letter ◽  
Thermodynamic Driving Force

Eshelby showed that the pointwise force F on and normal to the interface between a transformed inclusion and its surrounding matrix is the jump in the normal component of the elastic energy-momentum tensor across the interface. Gavazza later showed, using an entirely different approach, that this thermodynamic driving force F has a much simpler form involving only the average of the stress tensors at adjacent points on opposite sides of the interface and the “transformation strain” tensor. The equivalence of and connection between the two formulae was apparently first shown by Eshelby in a personal letter to Gavazza (attached as an appendix to this paper), although the brevity of the letter makes following Eshelby’s proof a little difficult. Here we expand Eshelby’s hitherto unpublished proof of the equivalence of the two expressions in what we believe is a clearer fashion.

Measurement and Modelling of Residual Stresses in Fracture Toughness Specimens Extracted From Large Components

2008 ◽  
Author(s):  
S. J. Lewis ◽  
S. Hossain ◽  
C. E. Truman ◽  
D. J. Smith ◽  
M. Hofmann
Keyword(s):  
Fracture Toughness ◽  
Residual Stress ◽  
Residual Stresses ◽  
Driving Force ◽  
Large Scale ◽  
Structural Integrity ◽  
Mechanical Load ◽  
Crack Driving Force ◽  
Neutron Diffraction Technique ◽  
Fracture Specimens

A number of previously published works have shown that the presence of residual stresses can significantly affect measurements of fracture toughness, unless they are properly accounted for when calculating parameters such as the crack driving force. This in turn requires accurate, quantitative residual stress data for the fracture specimens prior to loading to failure. It is known that material mechanical properties may change while components are in service, for example due to thermo-mechanical load cycles or neutron embrittlement. Fracture specimens are often extracted from large scale components in order to more accurately determine the current fracture resistance of components. In testing these fracture specimens it is generally assumed that any residual stresses present are reduced to a negligible level by the creation of free surfaces during extraction. If this is not the case, the value of toughness obtained from testing the extracted specimen is likely to be affected by the residual stress present and will not represent the true material property. In terms of structural integrity assessments, this can lead to ‘double accounting’ — including the residual stresses in both the material toughness and the crack driving force, which in turn can lead to unnecessary conservatism. This work describes the numerical modelling and measurement of stresses in fracture specimens extracted from two different welded parent components: one component considerably larger than the extracted specimens, where considerable relaxation would be expected as well as a smaller component where appreciable stresses were expected to remain. The results of finite element modelling, along with residual stress measurements obtained using the neutron diffraction technique, are presented and the likely implications of the results in terms of measured fracture toughness are examined.

Stored energy and its role in recrystallization process

2001 ◽  
Vol 9 (2) ◽  
pp. 61-64 ◽  
Author(s):  
K. Wierzbanowski ◽  
J. Tarasiuk ◽  
B. Bacroix ◽  
K. Sztwiertnia
Keyword(s):  
Recrystallization Process ◽  
Stored Energy
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