The Experts below are selected from a list of 11055 Experts worldwide ranked by ideXlab platform
Hong-liang Dai - One of the best experts on this subject based on the ideXlab platform.
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thermo elastic analysis of a functionally graded rotating hollow circular disk with variable thickness and angular speed
Applied Mathematical Modelling, 2016Co-Authors: Ting Dai, Hong-liang DaiAbstract:Abstract In this paper, the displacement and stress fields in a functionally graded material (FGM) hollow circular disk, rotating with an angular acceleration under a changing temperature field, are achieved by using a semi-analytical approach. The material properties are assumed to vary along the Radial Coordinate and related to the volume fraction of each material. The modulus of elasticity and the coefficient of thermal expansion are supposed to be temperature-dependent, while the Poisson's ratio is assumed to be constant. In numerical examples, effects of the functionally graded index, the geometric shape, the angular speed and the temperature boundary conditions to the displacement and stresses are considered. The results of this study may be useful for other investigations of rotating FGM circular disks with variable thickness.
Yuriy Povstenko - One of the best experts on this subject based on the ideXlab platform.
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axisymmetric solutions to fractional diffusion wave equation in a cylinder under robin boundary condition
European Physical Journal-special Topics, 2013Co-Authors: Yuriy PovstenkoAbstract:The axisymmetric time-fractional diffusion-wave equation with the Caputo derivative of the order 0 < α ≤ 2 is considered in a cylinder under the prescribed linear combination of the values of the sought function and the values of its normal derivative at the boundary. The fundamental solutions to the Cauchy, source, and boundary problems are investigated. The Laplace transform with respect to time and finite Hankel transform with respect to the Radial Coordinate are used. The solutions are obtained in terms of Mittag-Leffler functions. The numerical results are illustrated graphically.
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nonaxisymmetric solutions of the time fractional heat conduction equation in a half space in cylindrical Coordinates
Journal of Mathematical Sciences, 2012Co-Authors: Yuriy PovstenkoAbstract:UDC 539.3 Nonaxisymmetric solutions of the time-fractional heat conduction equation with source term in cylindrical Coordinates are obtained for a half-space. The solutions are found using the Laplace transform with respect to time, the Hankel transform with respect to the Radial Coordinate, the finite Fourier transform with respect to the angular Coordinate, and the sine or cosine Fourier transform with respect to the bulk Coordinate. Numerical results are illustrated graphically.
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non central symmetric solution to time fractional diffusion wave equation in a sphere under dirichlet boundary condition
Fractional Calculus and Applied Analysis, 2012Co-Authors: Yuriy PovstenkoAbstract:The time-fractional diffusion-wave equation is considered in a sphere in the case of three spatial Coordinates r, µ, and φ. The Caputo fractional derivative of the order 0 < α ≤ 2 is used. The solution is found using the Laplace transform with respect to time t, the finite Fourier transform with respect to the angular Coordinate φ, the Legendre transform with respect to the spatial Coordinate µ, and the finite Hankel transform of the order n + 1/2 with respect to the Radial Coordinate r. In the central symmetric case with one spatial Coordinate r the obtained result coincides with that studied earlier. Numerical results are illustrated graphically.
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solutions to diffusion wave equation in a body with a spherical cavity under dirichlet boundary condition
An International Journal of Optimization and Control: Theories & Applications (IJOCTA), 2011Co-Authors: Yuriy PovstenkoAbstract:Solutions to time-fractional diffusion-wave equation with a source term in spherical Coordinates are obtained for an infinite medium with a spherical cavity. The solutions are found using the Laplace transform with respect to time t, the finite Fourier transform with respect to the angular Coordinate I•, the Legendre transform with respect to the spatial Coordinate μ, and the Weber transform of the order n+1/2 with respect to the Radial Coordinate r. In the central symmetric case with one spatial Coordinate r the obtained results coincide with those studied earlier.
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solutions to time fractional diffusion wave equation in cylindrical Coordinates
Advances in Difference Equations, 2011Co-Authors: Yuriy PovstenkoAbstract:Nonaxisymmetric solutions to time-fractional diffusion-wave equation with a source term in cylindrical Coordinates are obtained for an infinite medium. The solutions are found using the Laplace transform with respect to time , the Hankel transform with respect to the Radial Coordinate , the finite Fourier transform with respect to the angular Coordinate , and the exponential Fourier transform with respect to the spatial Coordinate . Numerical results are illustrated graphically.
A Zhidenko - One of the best experts on this subject based on the ideXlab platform.
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new parametrization for spherically symmetric black holes in metric theories of gravity
Physical Review D, 2014Co-Authors: Luciano Rezzolla, A ZhidenkoAbstract:We propose a new parametric framework to describe in generic metric theories of gravity the spacetime of spherically symmetric and slowly rotating black holes. In contrast to similar approaches proposed so far, we do not use a Taylor expansion in powers of $M/r$, where $M$ and $r$ are the mass of the black hole and a generic Radial Coordinate, respectively. Rather, we use a continued-fraction expansion in terms of a compactified Radial Coordinate. This choice leads to superior convergence properties and allows us to approximate a number of known metric theories with a much smaller set of coefficients. The measure of these coefficients via observations of near-horizon processes can be used to effectively constrain and compare arbitrary metric theories of gravity. Although our attention is here focussed on spherically symmetric black holes, we also discuss how our approach could be extended to rotating black holes.
Ting Dai - One of the best experts on this subject based on the ideXlab platform.
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thermo elastic analysis of a functionally graded rotating hollow circular disk with variable thickness and angular speed
Applied Mathematical Modelling, 2016Co-Authors: Ting Dai, Hong-liang DaiAbstract:Abstract In this paper, the displacement and stress fields in a functionally graded material (FGM) hollow circular disk, rotating with an angular acceleration under a changing temperature field, are achieved by using a semi-analytical approach. The material properties are assumed to vary along the Radial Coordinate and related to the volume fraction of each material. The modulus of elasticity and the coefficient of thermal expansion are supposed to be temperature-dependent, while the Poisson's ratio is assumed to be constant. In numerical examples, effects of the functionally graded index, the geometric shape, the angular speed and the temperature boundary conditions to the displacement and stresses are considered. The results of this study may be useful for other investigations of rotating FGM circular disks with variable thickness.
Lihua You - One of the best experts on this subject based on the ideXlab platform.
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on rotating circular disks with varying material properties
Zeitschrift für Angewandte Mathematik und Physik, 2007Co-Authors: Lihua You, X Y You, Jian J ZhangAbstract:Taking Young’s modulus, thermal expansion coefficient and density to be the functions of the Radial Coordinate, a closed form solution of rotating circular disks made of functionally graded materials subjected to a constant angular velocity and a uniform temperature change is proposed in this paper. Excellent agreement with the solution from Mathematica 5.0 indicates the correctness of the proposed closed form solution. Distributions of the Radial displacement and stresses in the disks are determined with the proposed approach and how material properties, temperature change, geometric size and different material coefficients affect deformations and stresses is investigated.
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creep deformations and stresses in thick walled cylindrical vessels of functionally graded materials subjected to internal pressure
Composite Structures, 2007Co-Authors: Lihua You, Z Y ZhengAbstract:Abstract Steady-state creep of thick-walled cylindrical vessels made of functionally graded materials subjected to internal pressure is investigated in this paper. Taking material parameters involved in Norton’s law to be the functions of the Radial Coordinate, a simple and accurate method is developed from the strain rate–stress relations, Norton’s law, deformation compatibility condition and equilibrium equation of axisymmetric, plane strain problems. The proposed approach is employed to calculate stresses and creep strain rates in the thick-walled cylindrical vessels. How variations of material parameters along the Radial direction affect the stresses in the vessels is examined.