This study investigates geometrical non-linear analysis of composite circular cylindrical shells under external pressure over part of their surfaces and also shells subjected to combined axial compression and triangular external pressure. Donnell non-linear shell theory along with first order shear deformation theory (FOSD) are adopted in the analysis. In the case of combined axial compression ...

Organic/inorganic composite particles with a core–shell structure exhibit potential applications in chemical mechanical polishing/planarization (CMP) for mechanically challenging materials (copper and low-k dielectrics etc.). In this work, the spherical composites comprised of polystyrene (PS) cores and mesoporous silica (mSiO2) shells were synthesized through a self-assembly of cetyltrimethyla...

In the present research, the elastic buckling of composite cross-ply elliptical cylindrical shells under axial compression is studied through finite element approach. The formulation is based on shear deformation theory and the serendipity quadrilateral eight-node element is used to study the elastic behavior of elliptical cylindrical shells. The strain-displacement relations are accurately acc...

There is a strong requirement for more robust, lighter and cheaper launch vehicle structures. Unstiffened composite cylindrical shells, which are essential to the fabrication of launch vehicle airframes, are prone to buckling and are highly sensitive to imperfections which arise during the manufacturing process. The buckling load is an important characteristic in design, and may vary drasticall...

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...

This paper presents an experimental study of imperfection insensitive composite wavy cylindrical shells subject to axial compression. A fabrication technique for making cylindrical shells with intricate shape of cross-sections has been developed. A photogrammetry technique to measure the geometric imperfections has also been developed. The behavior of the wavy shells under axial compression was...

Torsional vibrations of composite poroelastic dissipative spherical shell are investigated in the framework of Biot’s extension theory.Here composite poroelastic spherical shell consists of two spherical shells, one is placed on other, and both are made of different poroelastic materials. Consideration of the stress-free boundaries of outer surface and the perfect bonding between two shells lea...

Diatoms are generally known for superior mechanical properties of their mineralised shells. Nevertheless, many copepod crustaceans are able to crush such shells using their mandibles. This ability very likely requires feeding tools with specific material compositions and properties. For mandibles of several copepod species silica-containing parts called opal teeth have been described. The prese...

Abstract— The present study is devoted for the development of a mathematical model to predict the structural behavior and critical pressure of composite cylindrical shell under external pressure using finite element analysis. The composites can be tailored to match the external loading. The effect of fibre orientation angle along with stacking sequence of the composites on the loading carrying ...

In this paper, natural frequency and response of forced vibration of composite laminated conical shells under different boundary conditions are investigated. To this end, equations of Donnell's thin shell theory are used as governing equations. The analytical Galerkin method together with beam mode shapes as weighting functions is employed to solve the problem. Due to importance of boundary con...