scholarly journals "Material" mechanics of materials

2002 ◽  
pp. 1-12 ◽  
Author(s):  
Gérard Maugin
Keyword(s):  
Phase Transition ◽  
Singular Point ◽  
Continuum Mechanics ◽  
Driving Force ◽  
Inhomogeneous Materials ◽  
Mechanics Of Materials ◽  
Recent Developments ◽  
Physical Effects ◽  
Transition Fronts ◽  
The Continuum

The paper outlines recent developments and prospects in the application of the continuum mechanics expressed intrinsically on the material manifold itself. This includes applications to materially inhomogeneous materials physical effects which, in this vision, manifest themselves as quasi-in homogeneities, and the notion of thermo dynamical driving force of the dissipative progress of singular point sets on the material manifold with special emphasis on fracture, shock waves and phase-transition fronts. .

scholarly journals Symmetries of Thirring Models on 3D Lattices

2022 ◽  
Author(s):  
Andreas Wilhelm Wipf ◽  
Julian Johannes Lenz
Keyword(s):  
Phase Transition ◽  
Order Parameter ◽  
Three Dimensions ◽  
Coupling Phase ◽  
Perturbative Methods ◽  
Dirac Materials ◽  
Recent Developments ◽  
Arbitrary Dimensions ◽  
Relativistic Fermi ◽  
The Continuum

We review some recent developments about strongly interacting relativistic Fermi theories in three spacetime dimensions. These models realize the asymptotic safety scenario and are used to describe the low-energy properties of Dirac materials in condensed matter physics. We begin with a general discussion of the symmetries of multi-flavor Fermi systems in arbitrary dimensions. Then we review known results about the critical flavor number $N_\mathrm{crit}$ of Thirring models in three dimensions. Only models with flavor number below $N_\mathrm{crit}$ show a phase transition from a symmetry-broken strong-coupling phase to a symmetric weak-coupling phase. Recent simulations with chiral fermions show that $N_\mathrm{crit}$ is smaller than previously extracted with various non-perturbative methods. Our simulations with chiral SLAC fermions reveal that for four-component flavors $N_\mathrm{crit}=0.80(4)$. This means that all reducible Thirring models with $\Nr=1,2,3,\dots$ show no phase transition with order parameter. Instead we discover footprints of phase transitions without order parameter. These new transitions are probably smooth and could be used to relate the lattice Thirring models to Thirring models in the continuum. For a single irreducible flavor, we provide previously unpublished values for the critical couplings and critical exponents.

Modeling the Biaxial Behavior of Concrete by Damage Mechanics with Poisson’s Ratio Variable

2015 ◽  
Vol 749 ◽  
pp. 391-397 ◽  
Author(s):  
Rebiha Smahi ◽  
Youcef Bouafia ◽  
Mohand Said Kachi
Keyword(s):  
Continuum Mechanics ◽  
Poisson’S Ratio ◽  
Damage Mechanics ◽  
Three Dimensional ◽  
Nonlinear Behavior ◽  
Poisson's Ratio ◽  
Biaxial Compression ◽  
Mechanics Of Materials ◽  
Linear Behavior ◽  
The Continuum

A new model is introduced, for predicting the nonlinear behavior of the concrete until the rupture. The non-linear behavior of the concrete is taken into account under monotonic load verifying the principles of the mechanics damage [1] and the concepts of the mechanics of the fracture, using the foundations of the continuum mechanics of materials [2]. The nonlinear mechanical behavior of the concrete in unidirectional is described by two laws (Sargin [3] for the compression and Grelat [4] on the tension). By introducing two variables of damage applied in unidirectional respectively in tension and in compression (Y. Bouafia , R. Smahi, and al., (2014)) [5]. Their combination with the laws of the continuum mechanics of materials (Hooke’s low generalized) [2], and the theory of the mechanics damage (theory of the isotropy of the damage, and principle of the equivalent deformation), brings us to a law of variation of the damage in three-directional applied in bidirectional. In addition, if the variation of the Poisson’s ratio of concrete in unidirectional compression has attracted the interest of several researchers we can cites: (Sami, A., Klink, 1975 [6], Murray D.W. 1979 [7], Niels Saabye ottosen, (1980) [8], Atheel E. Allos., L.H.Martin, (1981) [9], Ramtani.S, Y. Berthaud , J. Mazars, (1992) [10] and Ferretti, E., (2004) [11]. For the three-dimensional, we can mention: Chen 1982 [12], Guo 1997 [13], Zhu 1998 [14], Hyuk-Chun Noh, Hyo-Gyoung Kwak 2006 [15] and Ding Faxing Yu Zhiwu 2006 [16]. Confrontations of the calculations with experimental results (behavior of the concrete in biaxial compression and tension) have allowed to describe and to follow the real behavior of the concrete.

Mechanically Optimized Orientation of Intracellular Stress Fibers Under Cyclic Stretch

2000 ◽  
Author(s):  
Hiroshi Yamada ◽  
Tohru Takemasa ◽  
Takami Yamaguchi
Keyword(s):  
Endothelial Cell ◽  
Continuum Mechanics ◽  
Cellular Response ◽  
Length Change ◽  
Mechanical Stimulus ◽  
Stress Fiber ◽  
Cyclic Stretch ◽  
Stress Fibers ◽  
Biological Phenomenon ◽  
The Continuum

Abstract To elucidate the orientation of stress fibers in a cultured endothelial cell under cyclic stretch, we hypothesized that a stress fiber aligns so as to minimize the summation of its length change under cyclic stretch, and that there is a limit in the sensitivity of cellular response to the mechanical stimulus. Results from numerical simulations based on the continuum mechanics describe the experimental observations under uniaxial stretch well. They give us an insight to the biological phenomenon of the orientation in stress fibers under biaxial stretch from the viewpoint of mechanical engineering.

On shock waves and phase-transition fronts in continua

ARI ◽  
1998 ◽  
Vol 50 (3) ◽  
pp. 141-150 ◽  
Author(s):  
G. A. Maugin
Keyword(s):  
Phase Transition ◽  
Shock Waves ◽  
Transition Fronts

From Casimir Forces to Black-Body Radiation: Quantum and Thermal Fluctuations

2017 ◽  
Author(s):  
Alejandro W. Rodriguez ◽  
Adolfo Plasencia
Keyword(s):  
Driving Force ◽  
Black Body ◽  
Thermal Fluctuations ◽  
Black Body Radiation ◽  
Casimir Forces ◽  
Princeton University ◽  
Virtual Photons ◽  
Recent Developments ◽  
The Subject ◽  
Relationship Of

This dialogue with physicist Alejandro W. Rodríguez is in two parts. The first part, which took place in the MIT campus, reflects on how theory has been overtaking experimentation in recent developments in science. It also addresses the subject of the Casimir forces and their effects by using devices which benefit from them in everyday life. Later, Alejandro explains why the vacuum is not empty; and, what are the "virtual photons". In the second part, Alejandro explains his current research in the Department of Electrical Engineering of Princeton University, focusing on the black body; and quantum and thermal processes of electromagnetic fluctuations at the nanoscale, where the rules of quantum mechanics now hold sway. He is now studying quantum fluctuations and how the forces and energy exchanged between objects work. This all-important area is the current driving force for development in the field of thermovoltaic energy and thermal panels for capturing light; an area with a revolutionary potential capable of changing the existing relationship of humans with energy, technology and the environment, in other words, with the planet.

Research Subsidies and Innovation Improve Productivity

2016 ◽  
Vol 4 (2) ◽  
pp. 28-48
Author(s):  
Manoj Kumar
Keyword(s):  
Technological Change ◽  
Driving Force ◽  
Government Policies ◽  
Economics Of Innovation ◽  
Long Run ◽  
Edge Conditions ◽  
Recent Developments ◽  
Policy Impacts ◽  
Productivity Modeling

Most productivities theorists agree that understanding the economics of innovation and technological change is central to understanding why some suppliers grow faster than other suppliers. The driving force behind recent developments in innovation models of productivity is a desire to incorporate quality. Incorporating quality of produced products without the addition of restrictive razor's edge conditions implies that policy impacts the productivity. This paper makes productivity modeling along the lines of Barro and Becker (1989) and models an array of government policies to demonstrate how some policies can impact productivity in a productivity model without the addition of restrictive razor's edge conditions. In the author's model government policies are categorized according to whether they have profits only, profits and productivity, or no impact on profits and/or productivity. The model also predicts that a research subsidy promotes long run productivity.

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