Analys-ESS Pays Off

When I worked for a large electronics manufacturer they had vibration tables and these were large speaker drive units bolted to a big flat metal plate driven by an equally large audio amp and signal generator this could out put a single frequency or pulsed frequency. It could be programmed to vibrate at several different frequencies in turn. The test assembly was fixed in place and the safety cage put over the whole assembly before powering up. It had to be housed in a sound proof room so it did not disturb the whole site. They also had ovens and freezers humidity boxes and vacuum boxes. This was all to test for climatic conditioning. They also didfurther ageing tests on individual components. Guess who was dogs body.

If vibrating my designs is wrong, I don't want to be right. Not only is it necessary, it's fun. Analysis is great but it doesn't find the flaws in the assumptions that you used to make your analysis.

NASA has these, they are called G-tables, or vibration tables and they can shake the nuts off tightened bolts.

They are huge voice coil type drivers and amps, 250 KW and large excursions and frequency range.

http://www.swiftbat.org/xrays/programs/astroe/ph/XRS1/xph-vibx.html

http://astrophysics.gsfc.nasa.gov/xrays/programs/astroe/ph/XRS1/xph-shake-x.html

Have you seen the big shakers the Japenes use to simulate earth quakes they us big hydraulic rams. These are computer controlled and can simulate a whole house getting a good shake down.

Regards

All that testing of Niose-Level generated by Appliances is normally for Industrial, Mil-Eqpt, Aeronautical use but not for Domestic Appliances, because it adds a cost the user can not bear.

As for as Viberation & Environmental Tests like Temp, G-Tests, are also do not apply stricly on Fixes Plants where a lot of space is available for cooling & Screening etc etc.

The outfit I worked for were in the test and measurement business with big Millitary contracts.

Vibration testing is not especially expensive. Once you have a vibration machine, it only take about an hour to conduct your test. I'm sure most commercial companies don't bother though - who wants to build something that's going to last?