How would you test large vehicle for sinusoidal vibration

[nortel]

Hey, could anyone explain how you would preform a sinusoidal test on large vehicle (weight>40 tons). I have a graph from sinusoidal data, but i don't understant how they were able to obtain this information because there is not a powerful enough testing device.

 

[berkeman]

Hey, could anyone explain how you would preform a sinusoidal test on large vehicle (weight>40 tons). I have a graph from sinusoidal data, but i don't understant how they were able to obtain this information because there is not a powerful enough testing device.

How much does a Boeing 747 aircraft weigh?

http://www.worldwide-aviation.net/index.php?option=com_content&view=article&id=164:delayed-747-8-set-for-pre-flight-shake-tests&catid=39:ac-manufacturers&Itemid=68

There are some vibration test facilities for large/heavy vehicles. What vehicle do you have data on? Perhaps that manufacturer has a large test facility including a vibration test area, or else contracts out to some large test house?


EDIT -- A Boeing 747 weighs more than 40 tons:

http://www.boeing.com/commercial/747family/pf/pf_facts.html

.

 

[AlephZero]

You can buy hydraulic actuators that will apply 10 or 20 tonnes force at frequencies up to 100 or 200 Hz "off the shelf". That's more than enough for most vibration testing. You don't need to apply a 40-tonne force to shake a 40-tonne structure by a measurable amount.

This is a static load test not a vibration measurement, but it give an idea what sort of test rigs are built for special purposes: (It also show how much aircraft wings can bend before they break, which might be a surprise!)

 

[nortel]

Thanks for the examples and the help, It makes sense to me now.