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 Author: deajohn5556 Time: 08/22/07 00:34 PST This is a reply to message no. 19054 by tracylam Reply | Original Message | New Topic | List Topics | List Messages on This Topic
 Current Topic:Resonance TracyThe duration depends on the input acceleration.  At 1G input and a Q of 17 I calculate a metal stress of about 2000 psi,depending on the laminate.   Assuming the metal to fail, it depends on the static and  fatigue strength.  You would need about 20G input dwell at resonance to get the metal to reach 40,000 psi.   If that is the metal static strength it will fail right away, but if that is the fatigue strength it may take hours or forever unless you increase the load.  However, the failure may be dominated by the laminate matrix and shear failure, so the calculation is complex  inthat case.  At any rate its going to take a whopping load to fail that beam.  What is your acceleration input levcel at resonance? John