Mechanical resonance

It may cause violent swaying motions and potentially catastrophic failure in improperly constructed structures including bridges, buildings and airplanes.

Avoiding resonance disasters is a major concern in every building, tower and bridge construction project.

The Taipei 101 building for instance relies on a 660-ton pendulum—a tuned mass damper—to modify the response at resonance.

Buildings in seismic zones are often constructed to take into account the oscillating frequencies of expected ground motion.

Many clocks keep time by mechanical resonance in a balance wheel, pendulum, or quartz crystal.

A swing set is another simple example of a resonant system with which most people have practical experience.

Mechanical resonators work by transferring energy repeatedly from kinetic to potential form and back again.

Because of this repeated storage and additional energy input the system swings ever more strongly, until its load limit is exceeded.

The dramatic, rhythmic twisting that resulted in the 1940 collapse of "Galloping Gertie", the original Tacoma Narrows Bridge, is sometimes characterized in physics textbooks as a classic example of resonance.

[4] Such devices test an article or mechanism by subjecting it to a vibratory force for determining qualities, characteristics, or conditions thereof, or sensing, studying or making analysis of the vibrations otherwise generated in or existing in the article or mechanism.