Semi-analytical study of free vibration characteristics of shear deformable filament wound anisotropic shells of revolution

Free-Vibration Analysis of Ring-Stiffened Branched Composite Shells of Revolution

“…A comprehensive study of the effect of the variation of the stiffness coefficients on the buckling behavior of filament-wound conical shells was performed by Goldfield and Arbocz [4]. Recently, Kayran and Yavuzbalkan [11] studied the effect of the variation of stiffness coefficients on the free-vibration characteristics of filament-wound shells by a semi-analytical method based on the numerical integration of the governing equations.…”

“…Solution of the natural frequencies is accomplished by evaluating the determinant of the characteristic matrix for incremented values of frequency estimates within a frequency range of interest. When the finite exponential Fourier transform of the fundamental shell equations was used, it was observed that determinant of the characteristic matrix does not change sign; rather, it is always positive and vanishes at the eigenvalue [11]. Therefore, a slope change detection algorithm in combination with inverse interpolations was devised to extract the natural frequency.…”

“…Once an interval is determined, natural frequency is extracted by successive inverse interpolations. The details of the natural frequency extraction algorithm are described in [11]. It should be noted that extension of the multisegment numerical integration technique to the freevibration analysis of branched shells of revolution is simply accomplished by defining the transformation matrices TR at each junction j and modifying Eq.…”

“…For a general shell of revolution with arbitrary change of geometric and material properties along the meridian of the shell, thickness, radii of curvature, and stiffness coefficients depend on the meridional coordinate . The elements of the coefficient matrix K for a general shell of revolution with full macroscopically anisotropic laminated shell wall are given in the recent work of Kayran and Yavuzbalkan [11], and they will not be repeated here, for brevity. Application of the finite exponential Fourier transform to Eq.…”

Investigation of the Effect of Geodesic and Semi-geodesic Winding on the Vibration Characteristics of Variable Stiffness Filament Wound Shells of Revolution

“…Therefore, present study aims at presenting a comprehensive study of the effect of geodesic and semi-geodesic winding on the winding angle, stiffness and vibration characteristics of filament wound composite shells of revolution. The previous works of the authors 11,12 are extended by presenting additional results including the comparative study on the effect of taking constant winding angle and thickness versus using the actual variation of the winding angle and the thickness on the vibration characteristics. It should be noted that geodesic or semi-geodesic winding causes continuous meridional variation of the winding angle, thickness and the stiffness coefficients which also vary with the preset friction applied during the winding process.…”