The Tacoma Narrows Bridge Failure
The Tacoma Narrows Bridge was well known for its vertical oscillations; indeed, it earned the nickname ``Galloping Gertie'' because it would oscillate vertically in winds of only 3-4 miles per hour. On November 7, 1940, just four months after it opened, as the bridge was engaging in its usual vertical activity, the nature of the motion changed suddenly from pure vertical to pure torsional. This violent twisting motion persisted for about 45 minutes, changing occasionally from one-noded to no-noded twisting, and the bridge collapsed.
We argue that the motion of suspension bridges is governed by nonlinear partial differential equations and that the inherent nonlinearity yields the fascinating behavior that was observed at Tacoma Narrows, including:
Want to see a simulation of the bridge oscillations?
Here's some software that you can download that will allow you to experiment with the equations that govern the motion of a cross section of the suspension bridge.
Click here for more about my research.
ksmoore@umich.edu