The part about the explanation for the torsional motion not being the usual
forced resonance discussed in physics classes is correct. This definition of
aeronautical flutter from McGraw Hill Science & Technology Dictionary sounds
like the explanations I have read: "An aeroelastic, self-excited vibration
in which the external source of energy is the airstream and which depends on
the elastic, inertial, and dissipative forces of the system in addition to
the aerodynamic forces. Also known as flutter." See also Physics Teacher
article: What to Say About the Tacoma Narrows Bridge to Your Introductory
Physics Class by Bernard J. Feldman and Twin Views of Tacoma Narrows Bridge
from http://www.aapt.org/Store/upload/tacoma_narrows2.pdf.
-----Original Message-----
From: phys-l-bounces@carnot.physics.buffalo.edu
[mailto:phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of Larry Smith
Sent: Wednesday, December 14, 2011 3:01 PM
To: phys-l
Subject: [Phys-l] Fwd: So it is not vortex shedding?