As a major structural dynamic criterion in designing thin shells, the fundamental frequency is maximized for a specified total structural mass. The general optimization problem of metallic conical shell structures with clamped / free ends has been treated formally among all other types of boundary conditions. Both stiffened and unstiffened constructions are examined with the effective design va...

Abstract Composite cylindrical shells, as key components, are widely employed in large rotating machines. However, due to the frequency bifurcations and dense spectra caused by rotation, nonlinear vibration usually has behavior of complex multiple internal resonances. In addition, varying temperature fields make responses system further difficult obtain. Therefore, resonances composite shells w...

In this article, a nonlinear dynamical investigation of porose functionally graded cylindrical panels using proposed analytical model is carried out. The material's properties are considered to be porosity-dependent and in the thickness direction, corresponding power-law distribution. classical shell theory, with geometrical shape von Karman–Donnell, employed get Lagrange motion equations. By a...

An extension of the Donnell and Wan analysis for the buckling of a shell with initial imperfections is presented for a mode of arbitrary profile. Results for a mode with 26 arbitrary parameters are given with charts of the stress-strain characteristics for cylinders with initial displacements of between one-eighth and five times the skin thickness of the cylinder. A direct optimisation of the e...

Reduced order models employing the Lagrange and POD reduced basis methods in numerical approximation and feedback control of systems are presented and numerically tested. The system under consideration is a thin cylindrical shell with surface-mounted piezoceramic actua-tors. Donnell-Mushtari equations, modiied to include Kelvin-Voigt damping, are used to model the system dynamics. Basis functio...

Revolutionary advances in technology have led to the use of functionally graded nanocomposite structural elements that operate at high temperatures and whose properties depend on position, such as cylindrical shells designed load-bearing elements. These require new mathematical modeling updated numerical calculations be performed using improved theories design time reliably apply The main goal ...

carbon nanotube is investigated based on an elastic multi-layer shell model with van der Waals interaction taken into consideration. The multi-walled carbon nanotube is described as an individual elastic shell and the interlayer friction is negligible between the inner and outer tubes in the proposed model. And the Donnell equations of cylindrical shells are employed to describe the nonlinear b...

Buckling is investigated of a long thin cylindrical shell under longitudinal compression as modelled by the von KK armm an{Donnell equations. Evidence is reviewed for the buckling being localised to some portion of the axial length. In accordance with this observed behaviour the equations are rst approximated circumferentially by a Galerkin procedure, whereupon cross-symmetric homoclinic soluti...

Recent results concerning the application of Lie transformation group methods to structural mechanics are presented. Focus is placed on the point Lie symmetries and conservation laws inherent to the Bernoulli–Euler and Timoshenko beam theories as well as to the Marguerrevon Kármán equations describing the large deflection of thin elastic shallow shells within the framework of the nonlinear Donn...