&&ReWrAp:HEADERFOOTER:0:ReWrAp&&

Author

Hassan Morsy

Date of Award

1-2010

Degree Type

Thesis

Degree Name

Master of Applied Science (MASc)

Department

Mechanical Engineering

Supervisor

Mohamed S. Hamed

Language

English

Abstract

p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Times} span.s1 {font: 11.5px Helvetica}

Using an integrated Tuned Liquid Damper (TLD)-Structure in-house developed numerical algorithm that has been validated against recent rigorous experimental tests, the TLD performance was analyzed when coupled with a vibrating Single Degree of Freedom (SDOF) body representing a civil structure. The numerical algorithm solves the full two dimensional Navier-Stokes equations with no linearization assumptions. It uses the Volume of Fluid method to reconstruct the free surface, and the Partial Cell Treatment method to model the effect of any obstructions. This study investigated the structure response when coupled to a TLD with and without a screen under harmonic excitations. Structure sway was found to decrease by 71 % in the case of a TLD without a screen, and 80% in the case of a TLD with one screen. The best screen configuration was then determined for the TLD-Structure coupling under non-hmmonic excitations, taking minimal structure sway and acceleration as the deciding criteria. Eighteen different cases considering different screen locations and solidities were investigated, and the case with one screen placed in the middle with a solidity of 0.4 proved to be the best.

The study also investigated the effect of fluid height on structure sway under a p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Times}

wide range of excitation amplitudes. Harmonic Excitations with amplitudes up to 3% of the tank length and fluid heights up to 40% of tank length were considered. The results showed better structure response with lower fluid heights in the case of low to moderate excitation amplitudes. With high excitation amplitudes, the results confirmed an opposite trend where higher fluid heights resulted in better structure response.

The numerical code was then modified to model a Sloped Bottom (SB) TLD using the Partial Cell Treatment method. The numerical model for the SB TLD has been validated against experimental data to ensure accuracy. Numerous cases have been considered to investigate structure response under the new configuration, and to analyze how a SB TLD compares to a standard TLD. The results showed an increased damping ratio and better structure response for SB TLDs, and a significant softening spring behaviour that is important upon excitation cessation.

McMaster University Library

Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS