by Wenlong Zhang This dissertation studied the interaction of nonuniform flows with propeller blades in a submerged elastic duct. The acoustic radiation from the duct is calculated and correlated to the flow nonuniformities and the propeller and duct characteristics. First, a benchmark problem is studied wherein the sound radiation from an infinite plate with or without ribs is examined for dif...

In the present work, study of the vibration of a functionally graded (FG) cylindrical shell made up of stainless steel, zirconia, and nickel is presented. Free vibration analysis is presented for FG cylindrical shells with simply supported-simply supported and clamped–clamped boundary condition based on temperature independent material properties. The equations of motion are derived by Hamilton...

In this paper, a study on the vibration of thin cylindrical shells made of a functionally gradient material (FGM) composed of stainless steel and nickel is presented. The effects of the FGM configuration are taken into account by studying the frequencies of two FG cylindrical shells. Type I FG cylindrical shell has nickel on its inner surface and stainless steel on its outer surface and Type II...

The present paper studies an optimization problem of dynamically loaded cylindrical tubes. This is a problem of linear elasticity theory. As we search for the optimal thickness of the tube which minimizes the displacement under forces, this is a problem of shape optimization. The mathematical model is given by a differential equation (ODE and PDE, respectively); the mechanical problem is descri...

Static cylindrical shells made of various types of matter are studied as sources of the vacuum Levi-Civita metrics. Their internal physical properties are related to the two essential parameters of the metrics outside. The total mass per unit length of the cylinders is always less than 1 4. The results are illustrated by a number of figures.

Cylindrical shells under uniaxial compression and spherical shells under equi-biaxial compression display the most extreme buckling sensitivity to imperfections. In engineering practice, the reduction of load carrying capacity due to imperfections is usually addressed by use of a knockdown factor to lower the critical buckling stress estimated or computed without accounting for imperfections. F...

ABSTRACT Fluid-loaded nested cylindrical shells are modelled using a doubled-walled cylindrical shell structure closed at each end by circular end plates and excited by a transverse force at one end. The effects of various influencing factors on the radiated sound power are examined corresponding to non-concentricity of the cylindrical shells, entrained fluid and rib connections in the annular ...