Using numerical and asymptotic methods, the lowest natural frequencies vibration modes of a structure consisting closed circular cylindrical shell with an end cap attached to it, having shape shallow spherical segment, are studied in paper. Three types vibrations described. Eigenfrequencies first type, close shell, were previous works. In this paper, we study forms second type (cylindrical shel...

Thermal buckling behavior of truncated conical liner reinforced by laminated composite is investigated in the presence of a general initial imperfection. For this purpose, the method of virtual work and first-order strain-deformation shell theory are employed to extract equilibrium equations. To this end, a finite element code is developed using the 3D 8-node shell element with six degrees of f...

A new method for obtaining the response of a baaed, uid{loaded, nite cylindrical shell using the nite element method is presented. The Galerkin nite element formulation for this problem utilizes a Neumann Green's function representation of the pressure loading on the shell. By representing the pressure loading in this manner, only the structure need be discretized. Both C 0 and C 1 nite element...

Cylindrical shells, unstiffened or stiffened with rings and/or stringers are commonly used in offshore structures as main loading-carrying members. Comprehensive theoretical work and experimental studies on the buckling behavior of cylindrical shells have been carried out in the past. The increasing offshore application of stiffened cylindrical shells has raised some new challenges that need to...

Bifunctional monodispersed Fe3O4 particles coated with an ultrathin Y2O3:Tb3+ shell layer were fabricated using a facile urea-based homogeneous precipitation method. The obtained composite particles were characterized by powder X-ray diffraction, transmission electron microscopy (TEM), quantum design vibrating sample magnetometry, and photoluminescence (PL) spectroscopy. TEM revealed uniform sp...

An NbC-Fe composite powder was synthesized from an Nb₂O₅/Fe/C mixture by electrochemical reduction and subsequent carbonization in molten CaCl₂-NaCl. The composite has a core-shell structure, in which NbC acts as the cores distributing in the Fe matrix. A strong bonding between NbC and Fe is benefit from the core-shell structure. The sintering and electrochemical reduction processes were invest...