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...

Overproduced reactive oxygen species (ROS) are closely related to various health problems including inflammation, infection, and cancer. Abnormally high ROS levels can cause serious oxidative damage to biomolecules, cells, and tissues. A series of nano- or microsized particles has been developed to reduce the oxidative stress level by delivering antioxidant drugs. However, most systems are ofte...

free vibration of simply supported circular cylindrical shell made of functionally graded material (fgm) under internal pressure was investigated. the effective material properties are assumed to vary continuously along the thickness direction according to a volume fraction power law distribution. first order shear deformation theory based on love's first approximation theory was utilized in th...

We have recently proposed a new concept for deployable reflectors consisting of a thin parabolic carbon-fibre-reinforced-plastic (CFRP) shell stiffened along the edge by an elastically collapsible stiffener. Here we show that a stiffener accounting for less than 10% of the total mass of the reflector increases the stiffness of the softest deformation mode of the deployed reflector by 48 times, ...

Different analytical approaches can be used to model the forced response of the beam-stiffened plates or shells that are commonly found in many practical structures from ships to aircraft. A popular method is to smear the mass and stiffness properties of the beam stiffeners to give an orthotropic plate or shell. This is simpler than modelling discrete stiffeners. This paper considers the exampl...

The high efficiency of monocoque cylindrical shells in carrying axial loads is curtailed by their extreme sensitivity to imperfections. For practical applications, this issue has been alleviated by introducing closely stiffened shells which, however, require expensive manufacturing. Here we present an alternative approach that provides a fundamentally different solution. We design symmetry-brea...

In the present research, a unified formulation for free vibration analysis of the bidirectional functionally graded conical and cylindrical shells and annular plates on elastic foundations is developed. To cover more individual cases and optimally tailored material properties, the material properties are assumed to vary in both the meridian/radial and transverse directions. The shell/plate is a...