Author: Poon, Wai-yin Sam
Title: Effect of anti-symmetric mode on dynamic snap-through of curved beam
Degree: Ph.D.
Year: 2004
Subject: Hong Kong Polytechnic University -- Dissertations
Structural dynamics
Girders -- Vibration
Department: Department of Civil and Structural Engineering
Pages: iii, 237 leaves : ill. (some col.) ; 30 cm
Language: English
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.
Rights: All rights reserved
Access: open access

Files in This Item:
File Description SizeFormat 
b17811235.pdfFor All Users12.59 MBAdobe PDFView/Open

Copyright Undertaking

As a bona fide Library user, I declare that:

  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.

By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

Show full item record

Please use this identifier to cite or link to this item: