Using the Frobenius series method (FSM), an analytical solution is developed to obtain mechanical stresses of thick spherical pressure vessels made of functionally graded materials (FGMs). The cylinder pressure vessel is subjected to uniform internal pressure. The modulus of elasticity is graded along the radial direction according to power functions of the radial direction. It is assumed that ...

Title of dissertation: Effect of Aggregate Inhomogeneity on Mechanical Properties of Asphalt Mixtures Haleh Azari, Doctor of Philosophy, 2005 Dissertation directed by: Professor Richard McCuen Department of Civil and Environmental Engineering Vertical and radial inhomogeneity of asphalt mixture components in laboratoryfabricated specimens have been of concern in asphalt mixture testing because ...

This study concentrates on the free pure radial vibrations of hollow spheres made of hypothetically functionally simple power rule graded materials having identical inhomogeneity indexes for both Young’s modulus and the density in an analytical manner. After offering the exact elements of the free vibration coefficient matrices for free-free, free-fixed, and fixed-fixed restraints, a parametric...

In this paper, a radially piezoelectric functionally graded rotating disk is investigated by the analytical solution. The variation of material properties is assumed to follow a power law along the radial direction of the disk. Two resulting fully coupled differential equations in terms of the displacement and electric potential are solved directly. Numerical results for different profiles of i...

In solutions of tetramethylammonium (TMA+) DNA (double stranded) without added low-molecular-weight salt, the counterion radial density is calculated using the cylindrical Poisson-Boltzmann equation with a distance-dependent quasimacroscopic dielectric permittivity. Comparisons with small-angle neutron scattering data indicate that any inhomogeneity in dielectric permittivity is confined to one...

The transient response of a hollow finite cylinder with radial and axial material inhomogeneity to a pulse of short duration is analyzed. The problem is solved in two steps. Radial inhomogeneity is treated first by dividing the cylinder into coaxial segments each with a constant modulus E which is allowed to vary from segment to segment. Transfer matrices relating variables at the two radial in...

We calculate the low-redshift Taylor expansion for the luminosity distance for an observer at the center of a spherically symmetric matter inhomogeneity with a nonvanishing cosmological constant. We then test the accuracy of the formulas comparing them to the numerical calculation for different cases for both the luminosity distance and the radial coordinate. The formulas can be used as a start...

A semi-analytical iterative method as one of the newest analytical methods is used for the elastic analysis of thick-walled spherical pressure vessels made of functionally graded materials subjected to internal pressure. This method is accurate, fast and has a reasonable order of convergence. It is assumed that material properties except Poisson’s ratio are graded through the thickness directio...

We demonstrate a modulation of thermoelectric power factor via a radial dopant inhomogeneity in B-doped Si nanowires. These nanowires grown via vapor-liquid-solid (VLS) method were naturally composed of a heavily doped outer shell layer and a lightly doped inner core. The thermopower measurements for a single nanowire demonstrated that the power factor values were higher than those of homogeneo...