PolyU IR

PolyU Institutional Repository >
Civil and Environmental Engineering >
CEE Theses >

Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/3459

Title: Effect of anti-symmetric mode on dynamic snap-through of curved beam
Authors: Poon, Wai-yin Sam
Subjects: Hong Kong Polytechnic University -- Dissertations
Structural dynamics
Girders -- Vibration.
Issue Date: 2004
Publisher: The Hong Kong Polytechnic University
Abstract: It is well known that the static stability of the initial symmetric buckled mode is significant affected by the onset of anti-symmetric displacement, but the dynamic effects of anti-symmetric modes on dynamic snap-through motion are less understood. The purpose of this investigation is to study the anti-symmetric response of a clamped-clamped buckled beam that is subjected to symmetric sinusoidal excitation. Using the two-mode equations with nonlinear coupling, the autoparametric response of the antisymmetric mode was solved with the aid of Runge-Kutta (RK-4) numerical integration method. The effects of the anti-symmetric mode of vibration on the dynamic snap-through motion were studied. Analytical and numerical studies were also carried out to explore the mechanism of the snap-through motion. Numerical experiments yielded the instability boundaries of dynamic snap-through motion for both single mode and two-mode modeling. Experimental results for a buckled beam were obtained by base excitation with a 6000 N shaker. The measurement of the anti-symmetric modes could be separated from the symmetric mode by special configuration of the strain gauge sensor systems. The analysis results show various characteristic features of phenomenon: (a) autoparametric responses occurred for large static buckled shape when the resonance frequency of symmetric mode was about twice that of anti-symmetric mode; (b) autoparametric responses were dominant at frequency half of the excitation; (c) autoparametric responses of anti-symmetric modes could be as high as the symmetric mode even though the excitation force was symmetric; and (d) autoparametric responses decrease the excitation force that is required to initiate dynamic snap-through motion. A comparison of the simulation results and the experimentally measured data yields excellent results and demonstrates the effectiveness of the modeling approach.
Degree: Ph.D., Dept. of Civil & Structural Engineering, The Hong Kong Polytechnic University, 2004
Description: iii, 237 leaves : ill. (some col.) ; 30 cm.
PolyU Library Call No.: [THS] LG51 .H577P CSE 2004 Poon
Rights: All rights reserved.
Type: Thesis
URI: http://hdl.handle.net/10397/3459
Appears in Collections:CEE Theses
PolyU Electronic Theses

Files in This Item:

File Description SizeFormat
b17811235_ir.pdfFor All Users (Non-printable) 12.6 MBAdobe PDFView/Open
b17811235_link.htmFor PolyU Users 162 BHTMLView/Open

Facebook Facebook del.icio.us del.icio.us LinkedIn LinkedIn

All items in the PolyU Institutional Repository are protected by copyright, with all rights reserved, unless otherwise indicated.
No item in the PolyU IR may be reproduced for commercial or resale purposes.


© Pao Yue-kong Library, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
Powered by DSpace (Version 1.5.2)  © MIT and HP
Feedback | Privacy Policy Statement | Copyright & Restrictions - Feedback