Vibration and critical speed of thin rotating cylindrical shell

• Main Author: Ng, Yong Ren.
• Other Authors: Ng Teng Yong
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Mechanical engineering::Mechanics and dynamics
• Online Access: http://hdl.handle.net/10356/17187
• Institution: Nanyang Technological University

A shell is a three-dimensional body that is bounded by two closely-spaced curved surfaces which allow the transmission of applied loads, making it the most efficient structure for bending in any direction for the same cross-sectional area and loading condition. In rotating shells, Coriolis acceleration, centrifugal acceleration and the hoop tension arise due to constant angular velocities, causing qualitative changes in the structural frequency and critical speed characteristics of the shells. These qualitative differences are reflected mathematically in the bifurcation of the natural frequencies of vibration. In this project, with Love-Kirchhoff hypotheses as the basis, the vibration and critical speed of rotating thin isotropic cylindrical shells using classical Love’s and Donnell’s shell theories were studied. By constructing trial functions satisfying the given boundary conditions, the classical Galerkin’s method was employed for the analyses. Different shell and loading parameters were then investigated before comparisons were made between these two shell theories. Good agreement with existing results for low length ratio and circumferential wave number was obtained. Also, rotating thin laminated composite cylindrical shells were examined.