Coupled Bending-Bending Vibrations of Pretwisted Non-uniform Beams

碩士 === 國立成功大學 === 機械工程研究所 === 84 === Based on the Bernoulli-Euler beam theory, the governing equations and associated boundary conditions for the coupled bending-bending vibration of nonuniform pretwisted cantilever beams of rectangular cro...

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Bibliographic Details
Main Authors: Hsian-Lee Chiou, 邱顯澧
Other Authors: Sen-Yung Lee
Format: Others
Language:zh-TW
Published: 1996
Online Access:http://ndltd.ncl.edu.tw/handle/86032222915496628193
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Summary:碩士 === 國立成功大學 === 機械工程研究所 === 84 === Based on the Bernoulli-Euler beam theory, the governing equations and associated boundary conditions for the coupled bending-bending vibration of nonuniform pretwisted cantilever beams of rectangular cross-section are derived. The explicit relations between the two flexural displacements are established. The two coupled differential equations are decoupled into two complete integral-differential equations expressed in two flexural displacements, respectively. While taking the limiting studies for the beam without pretwisting, the integral-differential equation is reduced to a fourth-order differential equation. Finally, we can get the closed-form solutions of the governing equations through the decoupled differential equations and boundary conditions. The frequency equation is expressed in terms of the eight fundamental solutions of the system. Finally, a semi-exact solution method is used to find natural frequencies of the system.