The paper illustrates the application of a combined adaptive particle swarm optimization (A-PSO) algorithm and the finite strip method (FSM) to the lay-up optimization of symmetrically fiber-metal laminated (FML) composite shallow shell panels for maximizing the fundamental frequency. To improve the speed of the optimization process, adaptive inertia weight was used in the particle swarm optimiz...

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...

in this study, the free vibration of partially fluid-filled laminated composite circular cylindrical shell with arbitrary boundary conditions has been investigated by using rayleigh-ritz method. the analysis has been carried out with strain-displacement relations based on love’s thin shell theory and the contained fluid is assumed irrotational, incompressible and inviscid. after determining the...

this study aims to investigate the effects of geometric imperfections on buckling of thin cylindrical shells due to global shear. to this end, more than 320 finite element models of cylindrical shells with different diameter to thickness ratios were prepared. random imperfections with different amplitudes were applied to numerical models. the results revealed that global buckling of cylindrical...

This study aimed to investigate the effects of stiffeners on buckling of thin cylindrical shells under uniform axial compression. To this end, more than 300 finite element models of stiffened cylindrical shells were prepared. The variables considered are shell thickness, number, dimension and the location of the vertical and horizontal stiffeners as well as circular symmetrical imperfections. R...

understanding how a cutout influences the load bearing capacity and buckling behavior of cylindrical shells is fundamental in the design of structural components used in automobiles, aircrafts, and marine structures. in this article, simulation and analysis of steel cylindrical shells with various lengths, include quasi elliptical cutout, subjected to axial compression were systematically carri...

Thin walled cylindrical shells are important components of industrial structures such as liquid storage tanks, silos, etc. Shell buckling is usually a major failure mode of thin walled shells under extreme loads such as earthquakes. Longitudinal and radial stiffeners are generally used in order to increase buckling capacity of thin walled shells. During an earthquake, cylindrical shells may exp...

In this paper, the plastic limit load of cylindrical shells with opening subject to combined bending moment and axial force are found by finite element method using ANSYS suite of program. The effect of various parameters such as the geometrical ratios of shell and the shape, size, axial and angular position of the opening on the limit load of cylindrical shells under various loading conditions...

Currently, lattice composite structures have many applications in aerospace industries. The present research analyzed the effect of an external skin consisting of a lattice’s cylindrical shell on the buckling strength of composite materials, both numerically and experimentally. Two classes of specimens, with and without external skins, were fabricated using the filament winding process. To find...