The Experts below are selected from a list of 135 Experts worldwide ranked by ideXlab platform
K Y Lee - One of the best experts on this subject based on the ideXlab platform.
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influences of the moving velocity and material property on frictionless contact problem of orthotropic materials indented by a moving punch
Archives of Mechanics, 2013Co-Authors: Y T Zhou, K Y Lee, Yong Hoon JangAbstract:In analyzing the contact behavior of a material indented by a moving punch, of much importance are the contributions of the moving velocity and material property. The present paper develops a smoothly moving contact model for orthotropic materials indented by a rigid punch. Based on fundamental solutions of each eigenvalue case, the mixed boundary-value problem is reduced to a Cauchy type singular integral equation by applying the Galilean Transformation and Fourier transform. Particularly, the exact solution of the obtained singular integral equation is presented, and closed-form expressions of the physical quantities are given for a flat punch and a cylindrical punch. Figures are plotted to show the influences of the moving velocity, material properties and other loadings on the contact behaviors and to reveal the surface damage mechanism, which may provide useful guidelines for material’s designing and optimization.
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contact problem for magneto electro elastic half plane materials indented by a moving punch part i closed form solutions
International Journal of Solids and Structures, 2012Co-Authors: Yueting Zhou, K Y LeeAbstract:Abstract A theoretical model is developed for the exact contact analysis of magneto-electro-elastic half-plane materials indented by a moving rigid punch in this paper, which is Part I of a series of papers. A numerical analysis based on this theoretical model will be presented in Part II. The Galilean Transformation and the Fourier sine and cosine transforms are applied to make the transient problem tractable. Detailed analyses of the eigenvalue distributions of the double-biquadrate order characteristic equation related to the magneto-electro-elastic governing equations are performed. Real fundamental solutions are derived for each eigenvalue distribution. The punch may have a flat or cylindrical profile and may be electrically and magnetically conducting, electrically conducting and magnetically insulating, electrically insulating and magnetically conducting, or electrically and magnetically insulating. For each type of punch, the singular integral equations are derived with the surface contact stress, surface electric charge, and/or surface magnetic induction inside the contact region as the unknown functions. Exact solutions to the system of integral equations are obtained. In particular, closed-form expressions for the stresses, electric displacements, and magnetic inductions in terms of fundamental functions are derived, which provide a scientific basis for the interpretation of the contact behaviors of multiferroic materials as will be shown in Part II of this series of papers.
Daniel M Greenberger - One of the best experts on this subject based on the ideXlab platform.
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inadequacy of the usual Galilean Transformation in quantum mechanics
Physical Review Letters, 2001Co-Authors: Daniel M GreenbergerAbstract:We show that the superselection rule in the Galilean Transformation, forbidding the superposition of states of different mass, in inconsistent with the nonrelativistic limit of the Lorentz Transformation. We also point out that the extra Galilean phase is merely the residue of the "twin-paradox" effect, which does not vanish nonrelativistically. In general, there are phase effects due to proper time differences, and effects due to mass-energy equivalence, that do not vanish nonrelativistically but that are not handled adequately by the Galilean Transformation.
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the inconsistency of the usual Galilean Transformation in quantum mechanics and how to fix it
Zeitschrift für Naturforschung A, 2001Co-Authors: Daniel M GreenbergerAbstract:It is shown that the generally accepted statement that one cannot superpose states of different mass in non-relativistic quantum mechanics is inconsistent. It is pointed out that the extra phase induced in a moving system, which was previously thought to be unphysical, is merely the non-relativistic residue of the “twin-paradox” effect. In general, there are phase effects due to proper time differences between moving frames that do not vanish non-relativistically. There are also effects due to the equivalence of mass and energy in this limit. The remedy is to include both proper time and rest energy non-relativistically. This means generalizing the meaning of proper time beyond its classical meaning, and introducing the mass as its conjugate momentum. The result is an uncertainty principle between proper time and mass that is very general, and an integral role for both concepts as operators in non-relativistic physics.
Jacek Cyranka - One of the best experts on this subject based on the ideXlab platform.
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stabilizing the long time behavior of the forced navier stokes and damped euler systems by large mean flow
Physica D: Nonlinear Phenomena, 2018Co-Authors: Jacek Cyranka, Piotr B Mucha, Edriss S Titi, Piotr ZgliczynskiAbstract:Abstract The paper studies the issue of stability of solutions to the forced Navier–Stokes and damped Euler systems in periodic boxes. It is shown that for large, but fixed, Grashoff (Reynolds) number the turbulent behavior of all Leray–Hopf weak solutions of the three-dimensional Navier–Stokes equations, in periodic box, is suppressed, when viewed in the right frame of reference, by large enough average flow of the initial data; a phenomenon that is similar in spirit to the Landau damping. Specifically, we consider an initial data which have large enough spatial average, then by means of the Galilean Transformation, and thanks to the periodic boundary conditions, the large time independent forcing term changes into a highly oscillatory force; which then allows us to employ some averaging principles to establish our result. Moreover, we also show that under the action of fast oscillatory-in-time external forces all two-dimensional regular solutions of the Navier–Stokes and the damped Euler equations converge to a unique time-periodic solution.
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stabilizing the long time behavior of the navier stokes equations and damped euler systems by fast oscillating forces
arXiv: Analysis of PDEs, 2016Co-Authors: Jacek Cyranka, Piotr B Mucha, Edriss S Titi, Piotr ZgliczynskiAbstract:Author(s): Cyranka, Jacek; Mucha, Piotr B; Titi, Edriss S; Zgliczynski, Piotr | Abstract: The paper studies the issue of stability of solutions to the Navier-Stokes and damped Euler systems in periodic boxes. We show that under action of fast oscillating-in- time external forces all two dimensional regular solutions converge to a time periodic flow. Unexpectedly, effects of stabilization can be also obtained for systems with stationary forces with large total momentum (average of the velocity). Thanks to the Galilean Transformation and space boundary conditions, the stationary force changes into one with time oscillations. In the three dimensional case we show an analogical result for weak solutions to the Navier- Stokes equations.
Piotr Zgliczynski - One of the best experts on this subject based on the ideXlab platform.
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stabilizing the long time behavior of the forced navier stokes and damped euler systems by large mean flow
Physica D: Nonlinear Phenomena, 2018Co-Authors: Jacek Cyranka, Piotr B Mucha, Edriss S Titi, Piotr ZgliczynskiAbstract:Abstract The paper studies the issue of stability of solutions to the forced Navier–Stokes and damped Euler systems in periodic boxes. It is shown that for large, but fixed, Grashoff (Reynolds) number the turbulent behavior of all Leray–Hopf weak solutions of the three-dimensional Navier–Stokes equations, in periodic box, is suppressed, when viewed in the right frame of reference, by large enough average flow of the initial data; a phenomenon that is similar in spirit to the Landau damping. Specifically, we consider an initial data which have large enough spatial average, then by means of the Galilean Transformation, and thanks to the periodic boundary conditions, the large time independent forcing term changes into a highly oscillatory force; which then allows us to employ some averaging principles to establish our result. Moreover, we also show that under the action of fast oscillatory-in-time external forces all two-dimensional regular solutions of the Navier–Stokes and the damped Euler equations converge to a unique time-periodic solution.
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stabilizing the long time behavior of the navier stokes equations and damped euler systems by fast oscillating forces
arXiv: Analysis of PDEs, 2016Co-Authors: Jacek Cyranka, Piotr B Mucha, Edriss S Titi, Piotr ZgliczynskiAbstract:Author(s): Cyranka, Jacek; Mucha, Piotr B; Titi, Edriss S; Zgliczynski, Piotr | Abstract: The paper studies the issue of stability of solutions to the Navier-Stokes and damped Euler systems in periodic boxes. We show that under action of fast oscillating-in- time external forces all two dimensional regular solutions converge to a time periodic flow. Unexpectedly, effects of stabilization can be also obtained for systems with stationary forces with large total momentum (average of the velocity). Thanks to the Galilean Transformation and space boundary conditions, the stationary force changes into one with time oscillations. In the three dimensional case we show an analogical result for weak solutions to the Navier- Stokes equations.
Yueting Zhou - One of the best experts on this subject based on the ideXlab platform.
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contact problem for magneto electro elastic half plane materials indented by a moving punch part i closed form solutions
International Journal of Solids and Structures, 2012Co-Authors: Yueting Zhou, K Y LeeAbstract:Abstract A theoretical model is developed for the exact contact analysis of magneto-electro-elastic half-plane materials indented by a moving rigid punch in this paper, which is Part I of a series of papers. A numerical analysis based on this theoretical model will be presented in Part II. The Galilean Transformation and the Fourier sine and cosine transforms are applied to make the transient problem tractable. Detailed analyses of the eigenvalue distributions of the double-biquadrate order characteristic equation related to the magneto-electro-elastic governing equations are performed. Real fundamental solutions are derived for each eigenvalue distribution. The punch may have a flat or cylindrical profile and may be electrically and magnetically conducting, electrically conducting and magnetically insulating, electrically insulating and magnetically conducting, or electrically and magnetically insulating. For each type of punch, the singular integral equations are derived with the surface contact stress, surface electric charge, and/or surface magnetic induction inside the contact region as the unknown functions. Exact solutions to the system of integral equations are obtained. In particular, closed-form expressions for the stresses, electric displacements, and magnetic inductions in terms of fundamental functions are derived, which provide a scientific basis for the interpretation of the contact behaviors of multiferroic materials as will be shown in Part II of this series of papers.
