iMechanica - Comments for "Collapse of the Tacoma Narrows Bridge, 7 November 1940"

Tacoma Bridge Failure was Due to Flutter

Madhukar Vable — Sun, 23 Dec 2007 09:43:07 +0000

In reply to Collapse of the Tacoma Narrows Bridge, 7 November 1940

Hope I do this right as I am new to this.

I believe the failure of
Tacoma Bridge was not due to resonance but due to
aerodynamic instability of flutter. [See Billah K.Y. and Scalan R.H. (1991) "Resonance, Tacoma Narrows Bridge Failure and Undergraduate Physics Textbooks" Am. J. Phys. Vol 59, No. 2, pp 118-124).

Flutter occurs when the
bending and torsion modes couple. In this coupled mode the
deformation causes the aerodynamic loads to increase which in turn
causes additional deformation and the cycle grows till the stucture
breaks. Today wind tunnel testing of suspension bridges is mandatory
but was not understood in bridge design at the time Tacoma Bridge was
built.

Madhu

Multiphysics (CFD + Structural) Software for Bridge Dynamics

Ondrej Kalny — Fri, 14 Dec 2007 06:12:06 +0000

In reply to Collapse of the Tacoma Narrows Bridge, 7 November 1940

In September, I attended IABSE (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.

ok, BridgeArt.net

Tacoma Narrows leads to the "Windbelt"

Mark E. Walter — Mon, 10 Dec 2007 18:06:31 +0000

In reply to Collapse of the Tacoma Narrows Bridge, 7 November 1940

A young inventor says that the Tacoma Narrows Bridge inspired him to invent the "Windbelt" to generate electricity.

http://www.humdingerwind.com/windbelt.html