Why You Can’t Ignore Those Vibration Fixture Resonances

Vibration fixtures, at times, have resonant frequencies that exist in the frequency range needed for conducting vibration tests. These resonant frequencies can cause significant problems when running vibration tests over ranges which include these resonances. A test engineer will attempt to control the shaker system through a feedback accelerometer which controls the level of vibration input into the test specimen. However, the control accelerometer can only control the level of vibration at that point. It cannot change the resonant behavior of the vibration fixture. Some problems involving this are described in this article along with some basic material about these phenomena.