The Experts below are selected from a list of 109233 Experts worldwide ranked by ideXlab platform

Bingen Yang - One of the best experts on this subject based on the ideXlab platform.

  • Semi-analytical solution of 2-D elasticity problems by the strip distributed transfer function method
    International Journal of Solids and Structures, 1996
    Co-Authors: Bingen Yang
    Abstract:

    Abstract A new technique, called the strip distributed transfer function method, is developed for static and dynamic analysis of two-dimensional elastic bodies that are composed of multiple rectangular subregions. The method is capable of modeling elastic regions of complex geometry and arbitrary boundary conditions, delivers highly accurate semi-analytical solutions and saves tremendous computer storage. In the analysis, a complex elastic region is first divided into a number of subregions; each subregion is then divided into finite strips. Through introduction of strip distributed transfer functions, the response of every subregion is presented in a semi-exact and closed form; the whole region is systematically assembled from the subregions, leading to a dynamic Equilibrium Equation. Solution of the Equilibrium Equation yields the semi-exact displacements and stresses of the elastic body. The proposed method is illustrated on a square region and an L-shaped region, and compared with the finite element method.

  • Strip distributed transfer function method for analysis of complex 2-D structures
    37th Structure Structural Dynamics and Materials Conference, 1996
    Co-Authors: Bingen Yang
    Abstract:

    An innovative semi-analytical solution technique, called the strip distributed transfer function method, is developed for static and dynamic analysis of complex two-dimensional flexible structures. The method is capable of modeling elastic continua of complex geometry and arbitrary boundary conditions, delivering highly accurate numerical, and saving tremendous computer storage. In the analysis, a complex elastic region is first divided into a number of subregions; each subregion is then divided into finite strips. Through introduction of strip distributed transfer functions, the response of every subregion is presented in a semi-exact and closed form; the whole region is systematically assembled from the subregions, leading to a dynamic Equilibrium Equation. Solution of the Equilibrium Equation yields the semi-exact displacements and stresses of the elastic body. The proposed method is illustrated in numerical examples, and compared with the finite element method and the finite strip method.

Iberê L. Caldas - One of the best experts on this subject based on the ideXlab platform.

  • Magnetohydrostatic Equilibrium with External Gravitational Fields in Symmetric Systems
    Brazilian Journal of Physics, 2016
    Co-Authors: F. F. De Carvalho, R. L. Viana, Iberê L. Caldas
    Abstract:

    We present a general formulation for magnetohydrostatic equilibria with external gravitational fields in symmetric systems with one ignorable coordinate, using non-orthogonal coordinate systems. We consider the cases of isothermal as well as adiabatic processes. Analytical exact solutions for the ideal magnetohydrodynamical Equilibrium Equation are presented for rectangular, cylindrical, and spherical coordinates.

  • MHD Equilibrium Equation in Symmetric Systems
    arXiv: Plasma Physics, 2011
    Co-Authors: M Y Kucinski, Iberê L. Caldas
    Abstract:

    In MHD symmetric systems the Equilibrium physical quantities are dependent on two variables only. In this cases it is possible to find a magnetic surface function that has the same symmetry. Under the assumption that the metric determinant is also independent of a third, ignorable coordinate, a general MHD Equilibrium Equation in curvilinear coordinates is deduced. This Equation is specially useful when non-orthogonal generalized coordinates are used.

J Rakowski - One of the best experts on this subject based on the ideXlab platform.

  • the interpretation of the shear locking in beam elements
    Computers & Structures, 1990
    Co-Authors: J Rakowski
    Abstract:

    Abstract A new concept of explanation of the shear locking phenomenon occurring in the Timoshenko beam is presented. Instead of element matrix analysis the global expression of the Equilibrium Equation for a whole beam is considered. Based on the element stiffness matrix the Equilibrium conditions for a regular discretized beam are derived in the form of one difference Equation that converges to the analytical differential formulation for the continuous beam. It is clearly shown that application of the linear shape functions leads to an overly stiff element in the Mindlin elements because this approximation converges to the solution of a different Equilibrium Equation. From the stiffness matrices of exactly and reduced integrated linear and quadratic elements the difference Equilibrium conditions are derived and they are compared with the exact Equations of the bending beam problem. For each type of element the improved one is elaborated that assures the exact solution for beams irrespective of beam thickness and discretization (number of elements). The numerical analyses for various boundary conditions, beam load, discretization and thickness ratios are given.

S Kwapisz - One of the best experts on this subject based on the ideXlab platform.

  • generalized desorption Equilibrium Equation of lignite in a wide temperature and moisture content range
    Fuel, 2011
    Co-Authors: Zdzislaw Pakowski, Robert Adamski, M Kokocinska, S Kwapisz
    Abstract:

    Abstract Brown coal is the most abundant and economically viable source of energy. To increase the efficiency of power generation from brown coal predrying of lignite is probably the first step to be taken. Both air drying, or more energy efficient superheated steam drying, may be considered. For the design of both processes an Equilibrium relationship between water activity, moisture content and temperature in a form of working desorption isotherm is needed. This work presents experimentally obtained results of sorption isotherms measurements at seven temperatures and one sorption isobar at atmospheric pressure obtained for Belchatow brown coal. These results were compared to the results obtained by other authors for Australian and USA coals and due to relatively close fit of all data points one generalized Equation of desorption Equilibrium was fitted covering a wide range of temperatures from 5 to 260 °C and moisture contents up to 1.5 kg/kg. Adsorption isotherms are not described by the same Equation since strong sorptional hysteresis was observed.

Hongxing Fan - One of the best experts on this subject based on the ideXlab platform.

  • pseudo Equilibrium Equation of calcium phosphate precipitation from aqueous solution
    Physical Chemistry Chemical Physics, 2019
    Co-Authors: Hongxing Fan, Baodi Gou, Yuxi Gao, Tianlan Zhang
    Abstract:

    An X-ray amorphous phase is frequently present at the early stage of calcium phosphate crystallization, and the relevant solution chemistry is essential for understanding the mechanism of reaction. Here, we report a quantitative study of a series of reaction systems at pseudo-Equilibrium states. We determined the composition of solutions and the quantities of the precipitate samples, and characterized the long- and short-range order of the precipitate using X-ray diffraction and synchrotron X-ray absorption near-edge structure spectroscopy, respectively. We found that, in a particle with multiple structural units, only a fraction of the units was able to reach pseudo-Equilibrium with the solution composition, which represents the average number of surficial clusters per unit. These findings enabled us to propose a general form of the Equilibrium constant Equation. The Equation fits the pseudo-Equilibrium data well, and it converts to the “solubility product (Ksp)” and the conventional “reaction quotient” in two limit cases, respectively. Further, using a cube model, we derived a “particle Equation” that reveals the connection between the particle structure and the form of Equilibrium constant Equation. The dependency of the form of pseudo-Equilibrium Equation on the structure and size of the precipitate reveals a fundamental relation in chemistry, and its applicability remains to be examined in other reaction systems, such as those involving nanocrystals and porous materials.