Your Web News in One Place

Help Webnuz

Referal links:

Sign up for GreenGeeks web hosting
December 16, 2015 12:00 am

Galloping Gertie, Engineering's Most Misunderstood Failure

tedlistens writes: Generations of physics teachers, textbooks, and articles have taught that the spectacular collapse of the Tacoma Narrows Bridge, 75 years ago, in November 1940, was caused by resonance. But this explanation is inaccurate, and despite the fact that the collapse is not a mystery—that the bridge, in a sense, twisted itself apart—the fallacy continues to spread. Not only that: according to a new study by Don Olson and colleagues at Texas State University and East Carolina University, parts of the famous footage that immortalized it are misleading too. According to the most complete recent research, he and his co-authors write, "the failure of the bridge was related to a wind-driven amplification of the torsional oscillation that, unlike a resonance, increases monotonically with increasing wind speed." Each time the deck of the bridge twisted now, it sought to return to its original position (inertial forces). And as it did so, twisting back with a matching speed and direction (elastic forces), the wind and the vortices caught it each time, pushing the deck just a little bit more in that direction (aerodynamic forces). With each twist and each twist back, the size of the twisting slightly increased.

Read more of this story at Slashdot.


Original Link: http://rss.slashdot.org/~r/Slashdot/slashdot/~3/TMBgub5gQkQ/galloping-gertie-engineerings-most-misunderstood-failure

Share this article:    Share on Facebook
View Full Article

Slashdot

Slashdot was originally created in September of 1997 by Rob "CmdrTaco" Malda. Today it is owned by Geeknet, Inc..

More About this Source Visit Slashdot