One of the many Environmental tests to which products are subjected is Vibration. These vibration tests are carried out using an Electrodynamic Vibration Test System, which in very simple terms is a Vibrator (Shaker, Thruster, Exciter), an Amplifier and a Controller.

As to what is Vibration Tested, it is probably easier to list what is not. If it is Electronic, Mechanical, or Electromechanical and is to be transported from A to B it will, at some time during its development or production, have been subjected to vibration tests: satellites, mobile phones, cars (all and component parts), aircraft, sharp pointed things which go bang, cans of beer with widgets and even boxes of chocolate, to name just a few.

The type of tests are many and varied, but they break down into several categories which are: Sine (Fixed Frequency, Swept, Resonance Dwell), Random (Broad Band / Narrow Band), Shock / Bump, Fixed Sine on Random (SOR), Swept Sine on Random, Swept Random on Random (ROR), Gunfire, Pyrotechnic Shock, Shock Response Spectrum (SRS), real time data and probably some more mixed mode tests which I can't think of at this moment.

It may be thought that performing a vibration test is just a matter of putting the product to be tested onto the vibrator/shaker, entering the test profile into the controller and pressing "Run". Unfortunately, this is a lot more complicated than it sounds, and only years of experience and detailed knowledge of the subject would enable you to setup and run a test correctly. Even the most experienced Vibration Test Engineers will tell you that there is always something to learn about the subject. The engineer who "knows it all" about Vibration Testing does not exist!

Richard Baker
PS I have run courses on this subject for 22 years, written VIBKIT to do all the calculations I need, and I still have things to learn!

Training: Untrained Vibration Test personnel are dangerous, not only to the Vibration Test System, but also to the Product Under Test!! Mistakes can be very expensive.

This subject is sometimes referred to as a "black art", it is not ! It is a complex science, understood by few, for those who don't they call it a black art.