Random Fatigue Testing

[Spirit]

hi all, i am a newbie at this site.
I have a question: we are testing a mechanical equipment to operative life fatigue using the PSD recovered during normal work. My question is: having to verify the reliability over all the lifecycle of the equipment, is it possible to test the item only to a limited time with a PSD environment modified, instead than the nominal PSD over all the operative life duration? Thx in advance.

 

[electricpete]

What I'm about to say is probably obvious. What you describe is a type of accelerated life testing. If you believe the failure mode is fatigue, then the failure should be dependent upon the number of cycles times the amplitude (I think). Increasing test amplitude by factor of 10 for example should allow you to complete a full life test in 1/10 of life. If anything you might push the equipment more into plastic deformation each cycle which I think would cause failure at lower value of cycles-times-amplitude then in real life.

 

[jeyaselvan]

That is what is called as accelerated life testing
Refer to MIL STD-810 standard for more details

Jeyaselvan