Relevant bibliographies by topics / Anisotropic energy

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Anisotropic energy'

Author: Grafiati
Published: 18 May 2024

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Anisotropic energy.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Anisotropic energy"

1

Zhang, Chao, Xiangzhuang Kong, Xian Wang, Yanxia Du, and Guangming Xiao. "A Predicting Model for the Effective Thermal Conductivity of Anisotropic Open-Cell Foam." Energies 15, no. 16 (August 22, 2022): 6091. http://dx.doi.org/10.3390/en15166091.

Full text
Abstract:
The structural anisotropy of open-cell foam leads to the anisotropy of effective thermal conductivity (ETC). To quantitatively analyze the effect of structural anisotropy on the anisotropy of ETC, a new predicting model for the ETC of anisotropic open-cell foam was proposed based on an anisotropy tetrakaidecahedron cell (ATC). Feret diameters in three orthogonal directions obtained by morphological analysis of real foam structures were used to characterize the anisotropy of ATC. To validate our proposed anisotropic model, the ETCs of real foam structures in three orthogonal directions predicted by it were compared with the numerical results, for which the structures of numerical models are reconstructed by X-ray computed tomography (X-CT). Using the present anisotropic model, the influences of the thermal conductivity ratio (TCR) and porosity of the foams on the anisotropic ratios of ETCs are also investigated. Results show that there is good consistency between the ETCs obtained by the anisotropic model and the numerical method. The maximum relative errors between them are 2.84% and 13.57% when TCRs are 10 and 100, respectively. The present anisotropic model can not only predict the ETCs in different orthogonal directions but also quantitatively predict the anisotropy of ETC. The anisotropies of the ETCs decrease with porosity because the proportion of the foam skeleton decreases. However, the anisotropies of ETCs increase with TCR, and there exist asymptotic values in anisotropic ratios of ETCs as TCR approaches infinity and they are equal to the relative Feret diameters in different orthogonal directions.
APA, Harvard, Vancouver, ISO, and other styles
2

Janhunen, P., A. Olsson, H. Laakso, and A. Vaivads. "Middle-energy electron anisotropies in the auroral region." Annales Geophysicae 22, no. 1 (January 1, 2004): 237–49. http://dx.doi.org/10.5194/angeo-22-237-2004.

Full text
Abstract:
Abstract. Field-aligned anisotropic electron distribution functions of T∥ > T⊥ type are observed on auroral field lines at both low and high altitudes. We show that typically the anisotropy is limited to a certain range of energies, often below 1keV, although sometimes extending to slightly higher energies as well. Almost always there is simultaneously an isotropic electron distribution at higher energies. Often the anisotropies are up/down symmetrical, although cases with net upward or downward electron flow also occur. For a statistical analysis of the anisotropies we divide the energy range into low (below 100eV), middle (100eV–1keV) and high (above 1keV) energies and develop a measure of anisotropy expressed in density units. The statistical magnetic local time and invariant latitude distribution of the middle-energy anisotropies obeys that of the average auroral oval, whereas the distributions of the low and high energy anisotropies are more irregular. This suggests that it is specifically the middle-energy anisotropies that have something to do with auroral processes. The anisotropy magnitude decreases monotonically with altitude, as one would expect, because electrons have high mobility along the magnetic field and thus, the anisotropy properties spread rapidly to different altitudes. Key words. Magnetospheric physics (auroral phenomena). Space plasma physics (wave-particle interactions; changed particle motion and acceleration)
APA, Harvard, Vancouver, ISO, and other styles
3

Song, Honghua, Yixin Zhao, Yaodong Jiang, and Jiehao Wang. "Scale Effect on the Anisotropy of Acoustic Emission in Coal." Shock and Vibration 2018 (December 18, 2018): 1–11. http://dx.doi.org/10.1155/2018/8386428.

Full text
Abstract:
Acoustic emission (AE) in coal is anisotropic. In this paper, we investigate the microstructure-related scale effect on the anisotropic AE feature in coal at unconfined loading process. A series of coal specimens were processed with diameters of 25 mm, 38 mm, 50 mm, and 75 mm (height to diameter ratio of 2) and anisotropic angles of 0°, 15°, 30°, 45°, 60°, and 90°. The cumulative AE counts and energy dissipation increase with the specimen size, while the energy dissipation per AE count behaves in the opposite way. This may result from the increasing amount of both preexisting discontinuities and cracks (volume/number) needed for specimen failure and the lower energy dissipation AE counts generated by them. The effect of microstructures on the anisotropies of AE weakens with the increasing specimen size. The TRFD and its anisotropy reduce as the specimen size increases, and the reduction of fractal dimension is most pronounced at the anisotropic angle of 45°. The correlation between TRFD and cumulative AE energy in the specimens with different sizes are separately consistent with the negative exponential equation proposed by Xie and Pariseau. With the specimen size gain, the reduction of the TRFD weakens with the increasing amount of cumulative absolute AE energy.
APA, Harvard, Vancouver, ISO, and other styles
4

Shaaban, S. M., and M. Lazar. "Whistler instabilities from the interplay of electron anisotropies in space plasmas: a quasi-linear approach." Monthly Notices of the Royal Astronomical Society 492, no. 3 (December 28, 2019): 3529–39. http://dx.doi.org/10.1093/mnras/stz3569.

Full text
Abstract:
ABSTRACT Recent statistical studies of observational data unveil relevant correlations between whistler fluctuations and the anisotropic electron populations present in space plasmas, e.g. solar wind and planetary magnetospheres. Locally, whistlers can be excited by two sources of free energy associated with anisotropic electrons, i.e. temperature anisotropies and beaming populations carrying the heat flux. However, these two sources of free energy and the resulting instabilities are usually studied independently preventing a realistic interpretation of their interplay. This paper presents the results of a parametric quasi-linear study of the whistler instability cumulatively driven by two counter-drifting electron populations and their anisotropic temperatures. By comparison to individual regimes dominated either by beaming population or by temperature anisotropy, in a transitory regime the instability becomes highly conditioned by the effects of both these two sources of free energy. Cumulative effects stimulate the instability and enhance the resulting fluctuations, which interact with electrons and stimulate their diffusion in velocity space, leading to a faster and deeper relaxation of the beaming velocity associated with a core heating in perpendicular direction and a thermalization of the beaming electrons. In particular, the relaxation of temperature anisotropy to quasi-stable states below the thresholds conditions predicted by linear theory may explain the observations showing the accumulation of these states near the isotropy and equipartition of energy.
APA, Harvard, Vancouver, ISO, and other styles
5

Rocha, Daniel, Nicolay Tanushev, and Paul Sava. "Anisotropic elastic wavefield imaging using the energy norm." GEOPHYSICS 82, no. 3 (May 1, 2017): S225—S234. http://dx.doi.org/10.1190/geo2016-0424.1.

Full text
Abstract:
Based on the energy conservation principle, we derive a scalar imaging condition for anisotropic elastic wavefield migration. Compared with conventional imaging conditions that correlate displacement components or potentials from source and receiver wavefields, the proposed imaging condition does not suffer from polarity reversal, which degrades the image quality after stacking over shots. Our imaging condition also accounts for the directionality of the wavefields in space and time, leading to the attenuation of backscattering artifacts, which commonly appear in elastic reverse time migration images in the presence of strong model contrasts. In addition, our new imaging condition does not require wave-mode decomposition, which demands significant additional cost for elastic wavefields in anisotropic media. To properly image structures, we rely on the anisotropy parameters used in migration, as one would do for any other imaging condition. Our imaging condition is suitable for arbitrary anisotropy. We show the successful application of the anisotropic energy imaging condition by performing numerical experiments on simple and complex geologic models. We compare its quality with conventional counterparts by simulating complex geologic settings with vertical or tilted transverse isotropy.
APA, Harvard, Vancouver, ISO, and other styles
6

Mishra, B., and S. K. Tripathy. "Anisotropic dark energy model with a hybrid scale factor." Modern Physics Letters A 30, no. 36 (November 3, 2015): 1550175. http://dx.doi.org/10.1142/s0217732315501758.

Full text
Abstract:
Anisotropic dark energy model with dynamic pressure anisotropies along different spatial directions is constructed at the backdrop of a spatially homogeneous diagonal Bianchi type V (BV) spacetime in the framework of General Relativity. A time varying deceleration parameter generating a hybrid scale factor is considered to simulate a cosmic transition from early deceleration to late time acceleration. We found that the pressure anisotropies along the y- and z-axes evolve dynamically and continue along with the cosmic expansion without being subsided even at late times. The anisotropic pressure along the x-axis becomes equal to the mean fluid pressure. At a late phase of cosmic evolution, the model enters into a phantom region. From a statefinder diagnosis, it is found that the model overlaps with [Formula: see text] at late phase of cosmic time.
APA, Harvard, Vancouver, ISO, and other styles
7

MAK, M. K., PETER N. DOBSON, and T. HARKO. "EXACT MODELS FOR ANISOTROPIC RELATIVISTIC STARS." International Journal of Modern Physics D 11, no. 02 (February 2002): 207–21. http://dx.doi.org/10.1142/s0218271802001317.

Full text
Abstract:
We present a class of exact solutions of the Einstein gravitational field equations describing spherically symmetric and static anisotropic stellar type configurations. The solution is represented in a closed integral form. The energy density and both radial and tangential pressure are finite and positive inside the anisotropic star. The energy density, radial pressure, pressure-density ratio and the adiabatic speed of sound are monotonically decreasing functions. Several stellar models with the anisotropy coefficient proportional to r2 are discussed, the values of the basic physical parameters of the star (radius, mass and red shift) and bound on anisotropy parameter is obtained.
APA, Harvard, Vancouver, ISO, and other styles
8

MOHAPATRA, RANJITA K., P. S. SAUMIA, and AJIT M. SRIVASTAVA. "ANALYZING FLOW ANISOTROPIES WITH EXCURSION SETS IN RELATIVISTIC HEAVY-ION COLLISIONS." Modern Physics Letters A 27, no. 29 (September 17, 2012): 1250168. http://dx.doi.org/10.1142/s0217732312501684.

Full text
Abstract:
We show that flow anisotropies in relativistic heavy-ion collisions can be analyzed using a certain technique of shape analysis of excursion sets recently proposed by us for CMBR fluctuations to investigate anisotropic expansion history of the universe. The technique analyzes shapes (sizes) of patches above (below) certain threshold value for transverse energy/particle number (the excursion sets) as a function of the azimuthal angle and rapidity. Modeling flow by imparting extra anisotropic momentum to the momentum distribution of particles from HIJING, we compare the resulting distributions for excursion sets at two different azimuthal angles. Angles with maximum difference in the two distributions identify the event plane, and the magnitude of difference in the two distributions relates to the magnitude of momentum anisotropy, i.e. elliptic flow.
APA, Harvard, Vancouver, ISO, and other styles
9

Hossienkhani, H., V. Fayaz, and A. Jafari. "Energy conditions and modified gravity in anisotropic universe." Canadian Journal of Physics 96, no. 2 (February 2018): 225–32. http://dx.doi.org/10.1139/cjp-2017-0375.

Full text
Abstract:
In this paper, energy conditions in a new [Formula: see text] modified gravity ([Formula: see text] and T represent the Gauss–Bonnet invariant and trace of the energy–momentum tensor, respectively) for anisotropic universe with perfect fluid are analyzed. In this model, we develop the general scheme for new [Formula: see text] modified gravity reconstruction from realistic anisotropic Bianchi type-I cosmology. Using de Sitter solution, the exact solutions of the field equations have been obtained. It is found that null and weak energy conditions are satisfied for the parameter range considered. As a result, the analyses show that the increase of anisotropy is attributed to the increase of weak energy condition.
APA, Harvard, Vancouver, ISO, and other styles
10

Burlakov, Victor M., and Alain Goriely. "Ligand-Assisted Growth of Nanowires from Solution." Applied Sciences 11, no. 16 (August 20, 2021): 7641. http://dx.doi.org/10.3390/app11167641.

Full text
Abstract:
We consider the development of ligand-assisted growth processes for generating shape-anisotropic nanomaterials. Using statistical mechanics, we analyze the conditions under which ligand-assisted growth of shape-anisotropic crystalline nanomaterials from solution can take place. Depending on ligand-facet interaction energy and crystal facet area, molecular ligands can form compact layers on some facets leaving other facets free. The growth process is then restricted to free facets and may result in significant anisotropy in crystal shape. Our study uncovers the conditions for ligand-assisted growth of nanoplatelets and nanowires from isotropic or anisotropic seed nanocrystals of cuboid shape. We show that in contrast to nanoplatelets, ligand-assisted growth of nanowires requires certain anisotropy in the ligand-facet interaction energy.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Anisotropic energy"

1

Strümpfer, Johan. "Computing free energy hypersurfaces for anisotropic intermolecular associations." Master's thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/6290.

Full text
Abstract:
Includes abstract.
Includes bibliographical references.
Adaptive reaction coordinate force biaisng methods have been previously used for calculating the free energy of conformation and chemical reactions amongst others. Here a generalized method is described that is able to produce free energies in multiple dimension, descriptively named the free energies from adaptive reaction coordinate forces (FEARCF) method. To illustrate it a multidemensional intermolecular orientational free energy surface is calculated, and it is demonstrated how to invesrigate complex systems such as protein conformation and liquids.
APA, Harvard, Vancouver, ISO, and other styles
2

Steiner, Pinckney Alston IV. "Anisotropic low-energy electron-enhanced etching of semiconductors in DC plasma." Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/27060.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Cai, Renye. "Original strain energy density functions for modeling of anisotropic soft biological tissue." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCA003/document.

Full text
Abstract:
Cette thèse a porté sur la construction de densités d'énergie de déformation permettant de décrire le comportement non linéaire de matériaux anisotropes tels que les tissus biologiques souples (ligaments, tendons, parois artérielles etc.) ou les caoutchoucs renforcés par des fibres. Les densités que nous avons proposées ont été élaborées en se basant sur la théorie mathématique des polynômes invariants et notamment sur le théorème de Noether et l'opérateur de Reynolds. Notre travail a concerné deux types de matériaux anisotropes, le premier avec une seule famille de fibre et le second avec quatre familles. Le concept de polyconvexité a également été étudié car il est notoire qu'il joue un rôle important pour s'assurer de l'existence de solutions. Dans le cas d'un matériau comportant une seule famille de fibre, nous avons démontré qu'il était impossible qu'une densité polynomiale de degré quelconque puisse prédire des essais de cisaillement avec un chargement parallèle puis perpendiculaire à la direction des fibres. Une densité polynomiale linéaire combinée avec une fonction puissance a permis de contourner cet obstacle. Dans le cas d'un matériau comportant quatre familles de fibre, une densité polynomiale a permis de prédire correctement des résultats d'essai en traction bi-axiale extraits de la littérature. Les deux densités proposées ont été implémentées avec la méthode des éléments finis et en langage C++ dans le code de calcul universitaire FER. Pour se faire, une formulation lagrangienne totale a été adoptée. L'implémentation a été validée par des comparaisons avec des solutions analytiques de référence que nous avons exhibée dans le cas de chargements simples conduisant à des déformations homogènes. Des exemples tridimensionnels plus complexes, impliquant des déformations non-homogènes, ont également été étudiés
This thesis has focused on the construction of strain energy densities for describing the non-linear behavior of anisotropic materials such as biological soft tissues (ligaments, tendons, arterial walls, etc.) or fiber-reinforced rubbers. The densities we have proposed have been developed with the mathematical theory of invariant polynomials, particularly the Noether theorem and the Reynolds operator. Our work involved two types of anisotropic materials, the first with a single fiber family and the second with a four-fiber family. The concept of polyconvexity has also been studied because it is well known that it plays an important role for ensuring the existence of solutions. In the case of a single fiber family, we have demonstrated that it is impossible for a polynomial density of any degree to predict shear tests with a loading parallel and then perpendicular to the direction of the fibers. A linear polynomial density combined with a power-law function allowed to overcome this problem. In the case of a material made of a four-fiber family, a polynomial density allowed to correctly predict bi-axial tensile test data extracted from the literature. The two proposed densities were implemented in C++ language in the university finite element software FER by adopting a total Lagrangian formulation. This implementation has been validated by comparisons with reference analytical solutions exhibited in the case of simple loads leading to homogeneous deformations. More complex three-dimensional examples, involving non-homogeneous deformations, have also been studied
APA, Harvard, Vancouver, ISO, and other styles
4

Fogli, Simone. "Forecasts on the dark energy anisotropic stress for the esa euclid survey." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/5614/.

Full text
Abstract:
The cosmological constant Λ seems to be a not satisfactory explanation of the late-time accelerated expansion of the Universe, for which a number of experimental evidences exist; therefore, it has become necessary in the last years to consider alternative models of dark energy, meant as cause of the accelerated expansion. In the study of dark energy models, it is important to understand which quantities can be determined starting from observational data, without assuming any hypothesis on the cosmological model; such quantities have been determined in Amendola, Kunz et al., 2012. In the same paper it has been further shown that it is possible to estabilish a relation between the model-independent parameters and the anisotropic stress η, which can be also expressed as a combination of the functions appearing in the most general Lagrangian for the scalar-tensor theories, the Horndeski Lagrangian. In the present thesis, the Fisher matrix formalism is used to perform a forecast on the constraints that will be possible to make on the anisotropic stress η in the future, starting from the estimated uncertainties for the galaxy clustering and weak lensing measurements which will be performed by the European Space Agency Euclid mission, to be launched in 2020. Further, constraints coming from supernovae-Ia observations are considered. The forecast is performed for two cases in which (a) η is considered as depending from redshift only and (b) η is constant and equal to one, as in the ΛCDM model.
APA, Harvard, Vancouver, ISO, and other styles
5

Xu, Hao. "Theoretical and numerical modeling of anisotropic damage in rock for energy geomechanics." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53035.

Full text
Abstract:
At present, most of the energy power consumed in the world is produced by fossil fuel combustion, which has raised increasing interest in renewable energy technologies, non-conventional oil and gas reservoirs, and nuclear power. Innovative nuclear fuels and reactors depend on the economical and environmental impacts of waste management. Disposals in mined geological formations are viewed as potential consolidated storage facilities before final disposition. Different stress paths during construction result in different kinds of failure mechanisms, which alter rock strength and induce anisotropy of rock elastic properties. Crack propagation in rock can be originated by these engineering activities (excavation, drilling, mining, building overburden), or by changes of the natural environment (tectonic processes, erosion or weathering). Damage is a mathematical variable that can represent a variety of microstructure changes, such as crack density, length, aspect ratio and orientation. The framework of Continuum Damage Mechanics allows modeling the resulting reduction in strength and stiffness, as well as the associated stress-induced anisotropy and irreversible deformation. This work presents a modeling framework for anisotropic crack propagation in rock, in conditions of stress typical of geological storage and oil and gas extraction. Emphasis is put on the prediction of the damage zone around cavities and ahead of pressurized fracture tips. An original model of anisotropic damage, the Differential Stress Induced Damage (DSID) model, is explained. The Drucker-Prager yield function is adapted to make the damage threshold depend on damage energy release rate and to distinguish between tension and compression strength. Flow rules are derived with the energy release rate conjugate to damage, which is thermodynamically consistent. The positivity of dissipation is ensured by using a non-associate flow rule for damage, while nonelastic deformation due to damage is computed by an associate flow rule. Stress paths simulated at the material point illustrate damaged stiffness and deformation variations in classical rock mechanics tests. The maximum likelihood method was employed to calibrate and verify the DSID model against stress-strain curves obtained during triaxial compression tests and uniaxial compression tests performed on clay rock and shale. Logarithmic transformation, normalization and forward deletion allowed optimizing the formulation of the DSID model, and reduce the number of damage constitutive parameters from seven to two for clay rock. The DSID model was implemented in ABAQUS Finite Element (FE) software. The iterative scheme was adapted in order to account for the non-linearities induce both by damage and damage-induced deformation. FE simulations of laboratory tests capture size an intrinsic anisotropy effects on the propagation of damage in rock. Smeared DSID zones representing shale delamination planes avoid some convergence problems encountered when modeling discontinuities with debonded contact surface elements. FE simulations of tunnel excavation, fracture propagation and borehole pressurization were performed to illustrate the evolution of the damage zone and the impact on energy dissipation, anisotropy of deformation, and loss of stiffness. Future work will focus on coupling the propagation of fractures with the evolution of the damage process zone, and on the transition from continuum damage to discrete fracture upon crack coalescence.
APA, Harvard, Vancouver, ISO, and other styles
6

Hamad, Wadwood Y. "Energy-balance equations for in-roll stresses for anisotropic materials in wound rolls." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60599.

Full text
Abstract:
This Thesis concerns itself with the thorough investigation of the effects of core material parameters on the structural behaviour of wound rolls in core-roll winding systems. The underlying theme in this work is the derivation, based on the theory of elasticity, of an analytic expression for the core material's elasticity modulus as a function of only material parameters and geometry.
The approach undertaken herein is purely theoretical and encompasses the rigorous analysis of principally two models; linear isotropic and anisotropic. As for the former, both planar and axisymmetric geometries are investigated; and in the case of the anisotropic model, an axisymmetric plane stress situation is studied. Moreover, finite-element modelling and analysis for the isotropic condition is carried out to confirm the theoretical findings. The objective is then to apply the results; namely, the inclusion of Poisson's ratio and elasticity modulus of the core material, to modify existing energy-balance roll structure formulae. This undertaking is called for if the aim is to have a valid winding model that simulates the actual winding process; i.e., one which incorporates sensing the presence of the core through layers of wound material. Results are further compared with existing winding models and conclusions are given.
APA, Harvard, Vancouver, ISO, and other styles
7

Pröchtel, Patrick. "Anisotrope Schädigungsmodellierung von Beton mit adaptiver bruchenergetischer Regularisierung Anisotropic damage modeling of concrete regularized by means of the adaptive fracture energy approach /." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1224751435667-29771.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Gamieldien, Mogamat Riedaa. "Parameterization of the Gay-Berne coarse-grained potential from atomistically detailed anisotropic free energy volumes." Doctoral thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/10567.

Full text
Abstract:
Includes bibliographical references.
Simulating a system of 300,000+ atoms, such as an explicitly solvated protein using all atom molecular dynamics on the microsecond time-scale, would require an enormous amount of computing power and specialized software, even with which would still require months of computing time. However, if the atomic degrees of freedom of the system can be reduced (or averaged) in some physically intuitive manner, while still retaining a connection with the underlying atomistic detail, microsecond simulations could be achieved within weeks or days. Coarse-graining, a sub-class of mesoscale modelling, is used to represent molecules in a reduced form as either regular spheroids (ellipsoids) or as continuum models, using specialized interaction potentials. The Gay-Berne is a one such coarse-grain potential, which has been particularly successful in that it has been used in modelling of liquid crystals, protein dynamics and lipid membrane and micelle formation...
APA, Harvard, Vancouver, ISO, and other styles
9

Stevenson, Kip Patrick. "Anisotropic potential energy surfaces for atmospheric gas : unsaturated hydrocarbon molecule interactions from differential scattering experiments /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/11613.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Li, Bin. "The variational approach to brittle fracture in materials with anisotropic surface energy and in thin sheets." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/393861.

Full text
Abstract:
Fracture mechanics of brittle materials has focused on bulk materials with isotropic surface energy. In this situation different physical principles for crack path selection are very similar or even equivalent. The situation is radically different when considering crack propagation in brittle materials with anisotropic surface energy. Such materials are important in applications involving single crystals, extruded polymers, or geological and organic materials. When this anisotropy is strong, the phenomenology of crack propagation becomes very rich, with forbidden crack propagation directions or complex sawtooth crack patterns. Thus, this situation interrogates fundamental issues in fracture mechanics, including the principles behind the selection of crack direction. Similarly, tearing of brittle thin elastic sheets, ubiquitous in nature, technology and daily life, challenges our understanding of fracture. Since tearing typically involves large geometric nonlinearity, it is not clear whether the stress intensity factors are meaningful or if and how they determine crack propagation. Geometry, together with the interplay between stretching and bending deformation, leads to complex behaviors, restricting analytical approximate solutions to very simplified settings and specific parameter regimes. In both situations, a rich and nontrivial experimental record has been successfully understood in terms of simple energetic models. However, general modeling approaches to either fracture in the presence of strong surface energy anisotropy or to tearing, capable of exploring new physics, have been lacking. The success of energetic simple models suggests that variational theories of brittle fracture may provide a unifying and general framework capable of dealing with the more general situations considered here. To address fracture in materials with strongly anisotropic surface energy, we propose a variational phase-field model resorting to the extended Cahn-Hilliard framework proposed in the context of crystal growth. Previous phase-field models for anisotropic fracture were formulated in a framework only allowing for weak anisotropy. We implement numerically our higher-order phase-field model with smooth local maximum entropy approximants in a direct Galerkin method. The numerical results exhibit all the features of strongly anisotropic fracture, and reproduce strikingly well recent experimental observations. To explore tearing of thin films, we develop a geometrically exact model and a computational framework coupling elasticity (stretching and bending), fracture, and adhesion to a substrate. We numerically implement the model with subdivision surface finite elements. Our simulations qualitatively and quantitatively reproduced the crack patterns observed in tearing experiments. Finally, we examine how shell geometry affects fracture. As suggested by previous results and our own phase-field simulations, shell shape dramatically affects crack evolution and the effective toughness of the shell structure. To gain insight and eventually develop new concepts for optimizing the design of thin shell structures, we derive the configurational force conjugate to crack extension for Koiter's linear thin shell theory. We identify the conservative contribution to this force through an Eshelby tensor, as well as non-conservative contributions arising from curvature.
La mécanica de fractura frágil se ha centrado en materiales tridimensionales con una energía de superficie isotrópica. En esta situación, los diferentes principios para la selección del camino de la fisura son muy similares, o incluso equivalentes. La situación es radicalmente opuesta cuando se considera la propagación de fisuras en medios con energía de superficie anisótropa. Estos materiales son importantes en aplicaciones que involucran materiales cristalinos, polímeros extrudidos, o materiales orgánicos y geológicos. Cuando la anisotropía es fuerte, el fenómeno de la propagación de fisuras es muy rico, con direcciones de propagación prohibidas o complejos patrones de ruptura en dientes de sierra. Por tanto, esta situación plantea cuestiones fundamentales en la mecánica de la fractura, incluyendo los principios de selección de la dirección de propagación de la fractura. Igualmente, el proceso de rasgado de láminas delgadas y frágiles, comunes en la naturaleza, la tecnología y la vida diaria, desafía nuestro entendimiento de la fractura. Dado que el rasgado de estas láminas típicamente involucra grandes no linealidades geométricas, no está claro si los factores de intensidad de esfuerzos son válidos o si, y en tal caso cómo determinan la propagación de fisuras. La interacción entre la geometría, las deformaciones y la curvatura da lugar a comportamientos complejos, lo que restringe las soluciones analíticas aproximadas a ejemplos muy simplificados y a regímenes de parámetros limitados. En ambas situaciones, se han podido interpretar experimentos no triviales con modelos energéticos simples. Sin embargo, no se ha profundizado en modelos generales de fractura en presencia de energía de superficie fuertemente anisótropa o en láminas delgadas, ambas interesantes por su capacidad para explorar nueva física. El mencionado éxito de los modelos energéticos simplificados sugiere que las teorías variacionales de fractura en medios frágiles pueden proveer un marco unificador para considerar situaciones más generales, como las que se consideran en este trabajo. Para caracterizar la fractura en materiales con energía de superficie fuertemente anisótropa, proponemos un modelo variacional de campo de fase basado en el modelo extendido de Cahn-Hilliard. Los modelos de campo de fase existentes para la fractura anisótropa fueron formulados en un contexto que sólo admite anisotropía débil. En este trabajo, implementamos numéricamente nuestro modelo de campo de fase de alto orden con aproximantes locales de máxima entropía en un método directo de Garlerkin. Los resultados numéricos muestran todas las características de fractura con anisotropía fuerte, y reproducen llamativamente bien las últimas observaciones experimentales. Para explorar el rasgado de láminas delgadas, desarrollamos un modelo geométricamente exacto y un esquema computacional que acopla elasticidad (estiramiento y flexión), fractura, y la adhesión a un substrato. Implementamos numéricamente el modelo con elementos finitos basados en superficies de subdivisión. Nuestras simulaciones reproducen los patrones de ruptura, tanto cualitativamente como cuantitativamente, observados en los experimentos de rasgado. Finalmente, examinamos cómo la geometría de la lámina afecta la fractura. Como ha sido sugerido en resultados previos y en nuestras propias simulaciones de campo de fase, la forma de la lámina afecta dramáticamente la evolución de fisuras y la resistencia efectiva del material. Para comprender mejor estos fenómenos y con el objetivo de desarrollar nuevos conceptos para la optimización del diseño de estructuras de láminas delgadas, derivamos la fuerza configuracional conjugada a la extensión de la fractura para la teoría lineal de láminas delgadas de Koiter. Identificamos las contribuciones conservativas a esta fuerza a través del tensor de Eshelby, así como las contriuciones no conservativas que aparecen por el efecto de la curvatura.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Anisotropic energy"

1

J, Eggleston J., Voorhees P. W, and National Institute of Standards and Technology (U.S.), eds. A phase-field model for high anisotropic interfacial energy. [Gaithersburg, MD]: U.S. Dept. of Commerce, Technology Administration, National Institute of Standards and Technology, 2001.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

J, Eggleston J., Voorhees P. W, and National Institute of Standards and Technology (U.S.), eds. A phase-field model for high anisotropic interfacial energy. [Gaithersburg, MD]: U.S. Dept. of Commerce, Technology Administration, National Institute of Standards and Technology, 2001.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

J, Eggleston J., Voorhees P. W. 1955-, and National Institute of Standards and Technology (U.S.), eds. A phase-field model for high anisotropic interfacial energy. [Gaithersburg, MD]: U.S. Dept. of Commerce, Technology Administration, National Institute of Standards and Technology, 2001.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

J, Eggleston J., Voorhees P. W. 1955-, and National Institute of Standards and Technology (U.S.), eds. A phase-field model for high anisotropic interfacial energy. [Gaithersburg, MD]: U.S. Dept. of Commerce, Technology Administration, National Institute of Standards and Technology, 2001.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

B, McFadden Geoffrey, and National Institute of Standards and Technology (U.S.), eds. The effect of anisotropic surface energy on the Rayleigh instability. [Gaithersburg, Md.]: U.S. Dept. of Commerce, Technology Administration, National Institute of Standards and Technology, 2002.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

B, McFadden Geoffrey, and National Institute of Standards and Technology (U.S.), eds. The effect of anisotropic surface energy on the Rayleigh instability. [Gaithersburg, Md.]: U.S. Dept. of Commerce, Technology Administration, National Institute of Standards and Technology, 2002.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

K, Yeung P., Brasseur James G, and Institute for Computer Applications in Science and Engineering., eds. Scale disparity and spectral transfer in anisotropic numerical turbulence. Hampton, VA: Institute for Computer Applications in Science and Engineering, NASA Langley Research Center, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

H, Tipping R., and United States. National Aeronautics and Space Administration., eds. Extension of the quasistatic far-wing line shape theory to multicomponent anisotropic potentials. [Washington, D.C: National Aeronautics and Space Administration, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

Hybrid anisotropic materials for wind power turbine blades. Boca Raton, Fla: CRC Press, 2012.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

M, Arnold Steven, and United States. National Aeronautics and Space Administration., eds. Driving force analysis in an infinite anisotropic plate with multiple crack interactions. [Washington, DC]: National Aeronautics and Space Administration, 1995.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Anisotropic energy"

1

Zhang, Pengfei, and Sheng Dai. "Mesoporous Carbon for Energy." In Anisotropic Nanomaterials, 425–45. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-18293-3_11.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Chopra, Harsh Deep, Jason N. Armstrong, and Susan Z. Hua. "Anisotropic Curie Temperature Materials (Plenary)." In Energy Technology 2013, 177–88. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118658352.ch20.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Kun, Yang, Huo Chunyong, Ji Lingkang, Li Yang, Zhang Jiming, and Ma Qiurong. "Characterization of Anisotropic Behavior for High Grade Pipes." In Energy Materials 2014, 759–65. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-48765-6_93.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Kun, Yang, Huo Chunyong, Ji Lingkang, Li Yang, Zhang Jiming, and Ma Qiurong. "Characterization of Anisotropic Behavior for High Grade Pipes." In Energy Materials 2014, 759–65. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2015. http://dx.doi.org/10.1002/9781119027973.ch93.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Pipkin, A. C. "Relaxed Energy Densities for Anisotropic Membranes." In Solid Mechanics and Its Applications, 333–38. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-015-8494-4_45.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Tauchert, Theodore R. "Energy Method, Anisotropic and Heterogeneous Plates." In Encyclopedia of Thermal Stresses, 1279–83. Dordrecht: Springer Netherlands, 2014. http://dx.doi.org/10.1007/978-94-007-2739-7_163.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Deb, Debabrata, Sourav Roy Chowdhury, Saibal Ray, Farook Rahaman, and B. K. Guha. "A Model for Anisotropic Strange Stars." In XXII DAE High Energy Physics Symposium, 65–68. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-73171-1_13.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Chen, Yi-Heng. "Macrocrack Microcrack Interaction in Dissimilar Anisotropic Materials." In Advances in Conservation Laws and Energy Release Rates, 171–202. Dordrecht: Springer Netherlands, 2002. http://dx.doi.org/10.1007/978-94-015-9908-5_5.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Degond, P., M. Lemou, and J. L. Lòpez. "Fluids with Multivalued Internal Energy: The Anisotropic Case." In Transport in Transition Regimes, 121–36. New York, NY: Springer New York, 2004. http://dx.doi.org/10.1007/978-1-4613-0017-5_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Smith, G. F., and R. S. Rivlin. "The Strain-Energy Function for Anisotropic Elastic Materials." In Collected Papers of R.S. Rivlin, 541–59. New York, NY: Springer New York, 1997. http://dx.doi.org/10.1007/978-1-4612-2416-7_36.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Anisotropic energy"

1

Snellings, Raimond. "Energy dependence of anisotropic flow." In Critical Point and Onset of Deconfinement. Trieste, Italy: Sissa Medialab, 2007. http://dx.doi.org/10.22323/1.029.0028.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Zeng, Jie, Jianchun Guo, Junchen Liu, Tao Zhang, Zhihong Zhao, Jishan Liu, and Zhongwei Chen. "A Strain-Driven Model for Anisotropic Permeability Evolution of Shale and Coal Incorporating Creep Deformation, Anisotropic Internal Swelling/Shrinkage, and Gas Rarefaction Effects." In SPE Conference at Oman Petroleum & Energy Show. SPE, 2024. http://dx.doi.org/10.2118/218594-ms.

Full text
Abstract:
Abstract Permeability of shale and coal is a main controlling factor for gas migration and is sensitive to effective stress, sorption/desorption-induced internal swelling/shrinkage (swelling/shrinkage at fracture/pore surfaces), and gas rarefaction effects. The dependence of gas permeability on effective stress and rarefaction effects has been extensively studied. However, the impacts of anisotropic strains and their time-dependent evolution (creep deformation) on permeability variation were still not fully understood, which makes it difficult to accurately predict permeability evolution and simulate gas transport, especially for deep coal. To fill this knowledge gap, a modified sugar-cube conceptual model that captures the structural anisotropy of coal and shale is used to develop a generic fully anisotropic strain-driven permeability model incorporating anisotropic creep deformation, directional internal matrix swelling/shrinkage, and gas rarefaction effects. The time-dependent creep deformation is described by the Nishihara quasi-static rheological model with elastic, viscoelastic, and visco-plastic strain elements. Unlike previous studies where anisotropic internal swelling/shrinkage is ignored or simulated by simply using three sets of independent Langmuir pressure and swelling strain constants, a mechanical-property-based swelling model is used to truly couple directional internal swelling/shrinkage strain with mechanical anisotropy according to the energy balance theory. The Beskok-Karniadakis model is employed to accurately characterize full-Knudsen-number-ranged gas rarefaction effects. The proposed permeability model is verified against coal permeability measurement data. Analyses results indicate that the permeability evolution in each direction shows unique features depending on the anisotropic structure, directional internal swelling, and mechanical properties. The permeability reduction contributed by three-stage creep deformation can be larger than 90%. Internal swelling strain variation in all directions also exhibits a noticeable impact on the magnitude of permeability, which is more obvious at the third stage. The overall influence of the gas rarefaction phenomenon turns heavier as time increase due to the continuous narrowing of flow channel. Due to its analytical feature, the proposed model is suitable for different permeability measurement conditions, including constant effective stress, constant confining pressure, and constant average pore pressure conditions. It can be easily incorporated into a more complex and realistic Multiphysics framework for field-scale simulation and well production prediction.
APA, Harvard, Vancouver, ISO, and other styles
3

DASSIOS, G., and K. S. KARADIMA. "THE ENERGY FUNCTIONALS FOR ANISOTROPIC SCATTERING." In Proceedings of the Seventh International Workshop. WORLD SCIENTIFIC, 2006. http://dx.doi.org/10.1142/9789812773197_0004.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Verbunt, Paul P. P. C., Carlos Sánchez-Somolinos, Dirk J. Broer, and Michael G. Debije. "Anisotropic light emissions in luminescent solar concentrators." In Optics for Solar Energy. Washington, D.C.: OSA, 2012. http://dx.doi.org/10.1364/ose.2012.st2a.7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Gao, Q., J. L. Tao, J. Y. Hu, and X. Yu. "Mechanical Behaviors of an Anisotropic Shale Rock." In Shale Energy Engineering Conference 2014. Reston, VA: American Society of Civil Engineers, 2014. http://dx.doi.org/10.1061/9780784413654.017.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Yu, X. "Field Borehole Testing of Anisotropic Shale Rock." In Shale Energy Engineering Conference 2014. Reston, VA: American Society of Civil Engineers, 2014. http://dx.doi.org/10.1061/9780784413654.033.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Liu, Qiang, Zhenchun Li, Min Zhang, Kai Zhang, and Xuecheng Xu. "Dynamically focused beam migration in anisotropic media." In First International Meeting for Applied Geoscience & Energy. Society of Exploration Geophysicists, 2021. http://dx.doi.org/10.1190/segam2021-3579781.1.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Chen, Yao, and Chen Xiangguo. "Numerical modelling energy reflection in stratified anisotropic media." In SEG Technical Program Expanded Abstracts 1999. Society of Exploration Geophysicists, 1999. http://dx.doi.org/10.1190/1.1820917.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Wendt, S. "Energy dispersive measurements of anisotropic diffraction mottling effects." In The 27th annual review of progress in quantitative nondestructive evaluation. AIP, 2001. http://dx.doi.org/10.1063/1.1373802.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Lin, Yuqing, Yuzhen Niu, Shuai Zhang, and Junhao Chen. "Anisotropic energy accumulation for stereoscopic image seam carving." In 2017 International Conference on 3D Immersion (IC3D). IEEE, 2017. http://dx.doi.org/10.1109/ic3d.2017.8251899.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Anisotropic energy"

1

McFadden, G. B., J. J. Eggleston, and P. W. Voorhees. A phase-field model for high anisotropic interfacial energy. Gaithersburg, MD: National Institute of Standards and Technology, 2001. http://dx.doi.org/10.6028/nist.ir.6706.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Mehrabadi, M. M., S. C. Cowin, and C. O. Horgan. Strain Energy Density Bounds for Linear Anisotropic Elastic Materials. Fort Belvoir, VA: Defense Technical Information Center, January 1993. http://dx.doi.org/10.21236/ada271050.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Gurski, K. F., and G. B. McFadden. The effect of anisotropic surface energy on the Rayleigh instability. Gaithersburg, MD: National Institute of Standards and Technology, 2002. http://dx.doi.org/10.6028/nist.ir.6892.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Munday, Lynn B., and Jaroslaw Knap. Anisotropic Dislocation Line Energy and Crack Tip Dislocation Nucleation in (alpha)RDX. Fort Belvoir, VA: Defense Technical Information Center, November 2013. http://dx.doi.org/10.21236/ada592063.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Biswas, Kaushik, Som S. Shrestha, Diana E. Hun, and Jerald Atchley. Experimental and numerical evaluations of the energy savings potential of thermally anisotropic composites. Office of Scientific and Technical Information (OSTI), May 2019. http://dx.doi.org/10.2172/1515652.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Hart, Carl, and Gregory Lyons. A tutorial on the rapid distortion theory model for unidirectional, plane shearing of homogeneous turbulence. Engineer Research and Development Center (U.S.), July 2022. http://dx.doi.org/10.21079/11681/44766.

Full text
Abstract:
The theory of near-surface atmospheric wind noise is largely predicated on assuming turbulence is homogeneous and isotropic. For high turbulent wavenumbers, this is a fairly reasonable approximation, though it can introduce non-negligible errors in shear flows. Recent near-surface measurements of atmospheric turbulence suggest that anisotropic turbulence can be adequately modeled by rapid-distortion theory (RDT), which can serve as a natural extension of wind noise theory. Here, a solution for the RDT equations of unidirectional plane shearing of homogeneous turbulence is reproduced. It is assumed that the time-varying velocity spectral tensor can be made stationary by substituting an eddy-lifetime parameter in place of time. General and particular RDT evolution equations for stochastic increments are derived in detail. Analytical solutions for the RDT evolution equation, with and without an effective eddy viscosity, are given. An alternative expression for the eddy-lifetime parameter is shown. The turbulence kinetic energy budget is examined for RDT. Predictions by RDT are shown for velocity (co)variances, one-dimensional streamwise spectra, length scales, and the second invariant of the anisotropy tensor of the moments of velocity. The RDT prediction of the second invariant for the velocity anisotropy tensor is shown to agree better with direct numerical simulations than previously reported.
APA, Harvard, Vancouver, ISO, and other styles
7

Hunt, A. G. Hydraulic Conductivity Distributions for Anisotropic Systems and Application to Tc Transport at the U.S. Department of Energy Hanford Site. Office of Scientific and Technical Information (OSTI), January 2006. http://dx.doi.org/10.2172/862059.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Hunt, Allen G. Applying distributions of hydraulic conductivity for anisotropic systems and applications to Tc Transport at the U.S. Department of Energy Hanford Site. Office of Scientific and Technical Information (OSTI), June 2008. http://dx.doi.org/10.2172/929303.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Aberg, Daniel, Babak Sadigh, and Lorin X. Benedict. On the Site-Decomposition of Magnetocrystalline Anisotropy Energy Using Ome-Electron Eigenstates. Office of Scientific and Technical Information (OSTI), October 2015. http://dx.doi.org/10.2172/1239183.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Edward A. Startsev and Ronald C. Davidson. Electromagnetic Weibel Instability in Intense Charged Particle Beams with Large Energy Anisotropy. Office of Scientific and Technical Information (OSTI), October 2003. http://dx.doi.org/10.2172/820112.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Anisotropic energy' for particular source types:
Journal articles Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography