Structural Engineering and Mechanics

Volume 28, Number 6, 2008, pages 749-765

DOI: 10.12989/sem.2008.28.6.749

Axisymmetric vibrations of layered cylindrical shells of variable thickness using spline function approximation

K.K. Viswanathan, Kyung Su Kim, Jang Hyun Lee, Chang Hyun Lee and Jae Beom Lee

Abstract

Free axisymmetric vibrations of layered cylindrical shells of variable thickness are studied using spline function approximation techniques. Three different types of thickness variations are considered namely linear, exponential and sinusoidal. The equations of axisymmetric motion of layered cylindrical shells, on the longitudinal and transverse displacement components are obtained using Love?s first approximation theory. A system of coupled differential equations on displacement functions are obtained by assuming the displacements in a separable form. Then the displacements are approximated using Bickley-spline approximation. The vibrations of two-layered cylindrical shells, made up of several types of layered materials and different boundary conditions are considered. Parametric studies have been made on the variation of frequency parameter with respect to the relative layer thickness, length ratio and type of thickness variation parameter.

Key Words

free vibration; cylindrical shell; spline method; variable thickness; eigenvalues.

Address

K.K. Viswanathan, Kyung Su Kim, Jang Hyun Lee, Chang Hyun Lee and Jae Beom Lee: Impact & Fatigue Fracture Lab., Department of Naval Architecture& Ocean Engineering, Inha University, #253, Yonghyun-dong, Nam-gu, Incheon 402-751, Korea