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 <title>iMechanica - Collapse of the Tacoma Narrows Bridge, 7 November 1940 - Comments</title>
 <link>http://imechanica.org/node/2443</link>
 <description>Comments for &quot;Collapse of the Tacoma Narrows Bridge, 7 November 1940&quot;</description>
 <language>en</language>
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 <title>Tacoma Bridge Failure was Due to Flutter</title>
 <link>http://imechanica.org/node/2443#comment-6155</link>
 <description>&lt;p&gt;
Hope I do this right as I am new to this.
&lt;/p&gt;
&lt;p&gt;
I believe the failure of&lt;br /&gt;
Tacoma Bridge was not due to&amp;nbsp; resonance but&amp;nbsp; due to&lt;br /&gt;
aerodynamic&amp;nbsp; instability&amp;nbsp; of flutter. [See Billah K.Y. and Scalan R.H. (1991) &amp;quot;Resonance, Tacoma Narrows Bridge Failure and Undergraduate Physics Textbooks&amp;quot; Am. J. Phys. Vol 59, No. 2, pp 118-124).
&lt;/p&gt;
&lt;p&gt;
Flutter occurs when the&lt;br /&gt;
bending and torsion modes couple. In this coupled mode the&amp;nbsp;&lt;br /&gt;
deformation causes the aerodynamic loads to increase which in turn&lt;br /&gt;
causes additional deformation and the cycle grows till the stucture&lt;br /&gt;
breaks. Today wind tunnel testing of suspension bridges is mandatory&lt;br /&gt;
but was not understood in bridge design at the time Tacoma Bridge was&lt;br /&gt;
built.
&lt;/p&gt;
&lt;p&gt;
&amp;nbsp;Madhu 
&lt;/p&gt;
&lt;p&gt;
&amp;nbsp;
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&lt;p&gt;
&amp;nbsp;
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&lt;br class=&quot;clear&quot; /&gt;</description>
 <pubDate>Sun, 23 Dec 2007 04:43:07 -0500</pubDate>
 <dc:creator>Madhukar Vable</dc:creator>
 <guid isPermaLink="false">comment 6155 at http://imechanica.org</guid>
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 <title>Multiphysics (CFD + Structural) Software for Bridge Dynamics</title>
 <link>http://imechanica.org/node/2443#comment-6135</link>
 <description>&lt;p&gt;
In September, I attended &lt;a href=&quot;http://www.iabse.org&quot; target=&quot;_blank&quot;&gt;IABSE&lt;/a&gt;  (International Association for Bridge and Structural Engineering) symposium in Germany. It was interesting to see several presentations dealing with advances in computational modeling of bridge dynamics. These programs combine CFD with structural models and are becoming so powerful that can virtually eliminate wind tunnel testing, at least during the conceptual design stages.
&lt;/p&gt;
&lt;p&gt;
ok, &lt;a href=&quot;http://www.bridgeart.net&quot;&gt;BridgeArt.net&lt;/a&gt;
&lt;/p&gt;
&lt;br class=&quot;clear&quot; /&gt;</description>
 <pubDate>Fri, 14 Dec 2007 01:12:06 -0500</pubDate>
 <dc:creator>Ondrej Kalny</dc:creator>
 <guid isPermaLink="false">comment 6135 at http://imechanica.org</guid>
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<item>
 <title>Tacoma Narrows leads to the &quot;Windbelt&quot;</title>
 <link>http://imechanica.org/node/2443#comment-6116</link>
 <description>&lt;p&gt;
A young inventor says that the Tacoma Narrows Bridge inspired him to invent the &amp;quot;Windbelt&amp;quot; to generate electricity.
&lt;/p&gt;
&lt;p&gt;
&lt;a href=&quot;http://www.humdingerwind.com/windbelt.html&quot;&gt;http://www.humdingerwind.com/windbelt.html&lt;/a&gt;
&lt;/p&gt;
&lt;p&gt;
&lt;a href=&quot;http://www.popularmechanics.com/technology/industry/4224763.html?series=37&quot;&gt;http://www.popularmechanics.com/technology/industry/4224763.html?series=37&amp;nbsp;&lt;/a&gt;
&lt;/p&gt;
&lt;p&gt;
&amp;nbsp;
&lt;/p&gt;
&lt;br class=&quot;clear&quot; /&gt;</description>
 <pubDate>Mon, 10 Dec 2007 13:06:31 -0500</pubDate>
 <dc:creator>Mark E. Walter</dc:creator>
 <guid isPermaLink="false">comment 6116 at http://imechanica.org</guid>
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<item>
 <title>Collapse of the Tacoma Narrows Bridge, 7 November 1940</title>
 <link>http://imechanica.org/node/2443</link>
 <description>&lt;p&gt;
In today&amp;#39;s class of complex analysis, my co-instructor Scott Norris was lecturing on resonance.&amp;nbsp; He mentioned a &lt;a href=&quot;http://www.youtube.com/watch?v=3mclp9QmCGs&quot;&gt;YouTube video of the Tacoma Narrows Bridge&lt;/a&gt;.&amp;nbsp; Also instructive is the &lt;a href=&quot;http://en.wikipedia.org/wiki/Tacoma_Narrows_Bridge&quot;&gt;entry of the bridge on Wikipedia&lt;/a&gt;.&amp;nbsp;
&lt;/p&gt;
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&lt;br class=&quot;clear&quot; /&gt;</description>
 <comments>http://imechanica.org/node/2443#comments</comments>
 <category domain="http://imechanica.org/taxonomy/term/437">video</category>
 <category domain="http://imechanica.org/taxonomy/term/1631">AM 105a</category>
 <pubDate>Mon, 10 Dec 2007 12:33:10 -0500</pubDate>
 <dc:creator>Zhigang Suo</dc:creator>
 <guid isPermaLink="false">2443 at http://imechanica.org</guid>
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