Structures subject to Vibratory Fatigue

[nde3rich]

PLEASE HELP!!!! I need a concise reference to determine if a structure which houses 16 rotating contactors would be considered staticlly loaded or cyclicly loaded when appling the visual examination acceptance criteria of D1.1. I have searched this forum with no results found....

 

[Ron]

Whether or not it is subject to vibration is not necessarily the issue, but the stress levels of both the static and vibratory (dynamic) conditions. You will need to know the frequency and magnitude of the vibrations over a spectrum that will affect your materials. This will require measurements of the vibration and computation of the stress levels. One easy way to do this is through dynamic strain monitoring. This will catch the peak stresses and will show their frequency.

As for references, I would suggest you start with Bruel and Kjaer's handbooks (free online at

http://www.bksv.com/Library/Primers.aspx

) or Rao's textbook on Mechanical Vibrations (

http://www.pearsonhighered.com/product?ISBN=0130489875

)

Good luck.