Application of mixed finite elements to spatially non-local model of inelastic deformations

2016 ◽  
Vol 7 (2) ◽  
pp. 183-201 ◽  
Author(s):  
E. V. Vtorushin
Keyword(s):  
Finite Elements ◽  
Mixed Finite Elements ◽  
Local Model ◽  
Non Local

On velocity selection for needle-crystals in a fully non-local model of solidification

1987 ◽  
Vol 48 (4) ◽  
pp. 547-552 ◽  
Author(s):  
B. Caroli ◽  
C. Caroli ◽  
C. Misbah ◽  
B. Roulet
Keyword(s):  
Local Model ◽  
Non Local ◽  
Selection For ◽  
Velocity Selection

Local and non-local damage model with extended stress decomposition for concrete

2021 ◽  
pp. 105678952199872
Author(s):  
Bilal Ahmed ◽  
George Z Voyiadjis ◽  
Taehyo Park
Keyword(s):  
Shear Stress ◽  
Degrees Of Freedom ◽  
Biaxial Loading ◽  
Damage Model ◽  
Local Model ◽  
Uniaxial Tensile ◽  
Gradient Theory ◽  
Principal Stresses ◽  
Stress Decomposition ◽  
Non Local

In this work, a new damage model for concrete is proposed with an extension of the stress decomposition (limited to biaxial cases), to capture shear damage due to the opposite signed principal stresses. To extract the pure shear stress, the assumption is made that one component of the shear stress is a minimum absolute of the two principal stresses. The opposite signed principal stresses are decomposed into shear stress and uniaxial tensile/compressive stress. A local model is implemented in Abaqus UMAT and it is further extended to a non-local model by utilization of the gradient theory. The concept of three length scales (tension, compression, and shear) is kept the same as the recently proposed nonlocal damage model by the authors. The nonlocal model is implemented in the Abaqus UEL-UMAT subroutine with an eight-node quadrilateral user-defined element, having five degrees of freedom at corner nodes (displacement in X/Y direction and tensile/compressive and shear nonlocal equivalent strain) and two degrees of freedom at internal nodes. Some examples of a local model including uniaxial and biaxial loading are addressed. Also, five examples of mixed crack mode and mode-I cracking are presented to comprehensively show the performance of this model.

A non-local model to analyse 2D and 3D microbuckling of long carbon fibre epoxy material

2021 ◽  
pp. 114531
Author(s):  
Jean-Claude Grandidier ◽  
Anil Bettadahalli Channakeshava ◽  
Roberta Mazziotta
Keyword(s):  
Carbon Fibre ◽  
Local Model ◽  
Epoxy Material ◽  
Non Local ◽  
2D And 3D

Symmetric coupling of boundary elements and Raviart-Thomas-type mixed finite elements in elastostatics

1996 ◽  
Vol 75 (2) ◽  
pp. 153-174 ◽  
Author(s):  
Ulrich Brink ◽  
Carsten Carstensen ◽  
Erwin Stein
Keyword(s):  
Finite Elements ◽  
Mixed Finite Elements ◽  
Boundary Elements

Does Science have to be Causal in Order to be Science? Reflections on Nina Azari's Questions

2009 ◽  
Vol 31 (3) ◽  
pp. 315-318
Author(s):  
Harald Walach
Keyword(s):  
Local Model ◽  
Non Local

Nina Azari in her commentary on our article in this issue “Spirituality: The Legacy of Parapsychology” has raised the issue of what it actually takes for something to be called science. Does causality come into the picture? If so, how does causality relate to our non-local model that seems to explicitly eschew the question of causality? The answer lies in what one is willing to accept as causality. If causality can be conceived broader than just efficient-mechanistic causality then certainly our model is causal. If one insists on efficient-mechanistic causality as the only and truly scientific notion of causality, it is not. But then, I would argue, this is a very restricted and also short sighted view which should be questioned, and eventually, disregarded. This is what we have set out to do.

A Discretization Scheme for a Quasi-Hydrodynamic Semiconductor Model

1997 ◽  
Vol 07 (07) ◽  
pp. 935-955 ◽  
Author(s):  
Ansgar Jüngel ◽  
Paola Pietra
Keyword(s):  
Finite Elements ◽  
Mixed Finite Elements ◽  
Exponential Fitting ◽  
Discretization Scheme ◽  
Drift Diffusion Model ◽  
Drift Diffusion ◽  
Current Conservation ◽  
Numerical Tests ◽  
Finite Elements Methods ◽  
Degenerate Type

A discretization scheme based on exponential fitting mixed finite elements is developed for the quasi-hydrodynamic (or nonlinear drift–diffusion) model for semiconductors. The diffusion terms are nonlinear and of degenerate type. The presented two-dimensional scheme maintains the good features already shown by the mixed finite elements methods in the discretization of the standard isothermal drift–diffusion equations (mainly, current conservation and good approximation of sharp shapes). Moreover, it deals with the possible formation of vacuum sets. Several numerical tests show the robustness of the method and illustrate the most important novelties of the model.

Numerical modeling of two-phase binary fluid mixing using mixed finite elements

2012 ◽  
Vol 16 (4) ◽  
pp. 1101-1124 ◽  
Author(s):  
Shuyu Sun ◽  
Abbas Firoozabadi ◽  
Jisheng Kou
Keyword(s):  
Numerical Modeling ◽  
Finite Elements ◽  
Mixed Finite Elements ◽  
Fluid Mixing ◽  
Two Phase ◽  
Binary Fluid

Non-Local Model Analysis of Heat Pulse Propagation and Simulation of Experiments in W7-AS

1999 ◽  
Vol 68 (2) ◽  
pp. 478-486 ◽  
Author(s):  
Takuya Iwasaki ◽  
Sanae-I. Itoh ◽  
Masatoshi Yagi ◽  
Kimitaka Itoh ◽  
Ulich Stroth
Keyword(s):  
Pulse Propagation ◽  
Model Analysis ◽  
Heat Pulse ◽  
Local Model ◽  
Non Local
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