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This article investigates the free vibration of the rotating, tapered, thin-walled, composite box beam. The structural model incorporates a number of non-classical effects, such as transverse shear, warping inhibition, non-uniformtorsional model, and rotary inertia.The results obtained in this article seek to clarify the effect of flap-twist coupling, taper ratio, slenderness ratio, angular velocity, fibre orientation, and hub ratio on natural frequencies and mode shapes of the rotating thin-walled composite beams. The results are expected to offer better predictions of the vibrational behaviour of these kinds of structures in general, and in the design of rotor blades of turbo machinery, in... 

An investigation of the possible performance improvements of thin walled composite beams through the use of the variable stiffness concept with curvilinear fiber is presented. The beams are constructed from a single-cell closed cross section and a number of non-classical effects such as material anisotropy, transverse shear, warping inhibition and nonuniform torsional model are considered in the beam model. The governing equations were derived by means of the extended Hamilton's principle. Also the extended Galerkin's method is used to solve governing equations. Composite beams subjected to different loading with given geometry and material properties are optimized for maximum failure load.... 

This paper investigates the static and dynamic characteristics of composite thin-walled beams that are constructed from a single-cell box. The structural model considered herein incorporates a number of nonclassical effects, such as material anisotropy, transverse shear, warping inhibition, nonuniform torsional model and rotary inertia. The governing equations were derived using extended Hamilton's principle and solved using extended Galerkin's method. The effects of fiber orientation on static deflection and natural frequencies are considered and a number of important conclusions are outlined. © 2007 Elsevier Ltd. All rights reserved  

Axial-torsional vibrations of rotating pretwisted thin-walled composite box beams exhibiting primary and secondary warping are investigated. Considering the nonlinear strain-displacement relations, the coupled nonlinear axial-torsional equations of motion are derived using Hamilton's principle. Ignoring the axial inertia term leads to differential equation of motion in terms of elastic torsion in the case of axially immovable beams. Centrifugal load in the presence of material anisotropy and pretwist angle leads to an induced static torque. The nonlinear equation should be linearized about the corresponding equilibrium state to obtain the linear differential equation of motion. Extended... 

The aeroelastic design of composite wings modeled as thin-walled beams is investigated through the use of curvilinear fiber. The structural model considers non-classical effects such as transverse shear, warping restraint, rotary inertia, nonuniform torsional model and also aerodynamic loads based on Wagner's function. In this paper, a linear spanwise variation of the fiber orientation resulting in a variable-stiffness structure is used to optimize the wing for maximum aeroelastic instability speed purpose, while manufacturing constraints are incorporated. Numerical results indicate improvements of aeroelastic stability of variable-stiffness wings over conventional, constant-stiffness ones  

In this study, the aeroelastic stability and response of an aircraft swept composite wing in subsonic compressible flow are investigated. The composite wing was modeled as an anisotropic thin-walled composite beam with the circumferentially asymmetric stiffness structural configuration to establish proper coupling between bending and torsion. Also, the structural model consists of a number of nonclassical effects, such as transverse shear, material anisotropy, warping inhibition, nonuniform torsional model, and rotary inertia. The finite state form of the unsteady aerodynamic loads have been modeled based on the indicial aerodynamic theory and strip theory in the subsonic compressible flow.... 

The aim of this study is to carry out the numerical computation of nonlinear normal modes for rotating pretwisted composite thin-walled beam in axial-torsional vibrations. The structural model considered here, incorporates a number of non-classical effects such as primary and secondary warping, non-uniform torsional model, rotary inertia and pretwist angle. Ignoring the axial inertia term leads to differential equation of motion in terms of angle of twist in the case of axially immovable beam ends. The governing differential equations of motion are derived using Hamilton's principle and the reduced model around the static equilibrium position is obtained using 2-mode Galerkin discretization...