Bounding Grms Evaluation

[dthom0425]

Hi all,

Apologies if this is posted elsewhere already.

I can't share much details but my current design is able to withstand a random endurance vibration of 10 Grms for 2 hours. My customer is asking for us to increase to 50 Grms for 30 minutes.

Can someone explain to me how I would go about comparing the two differing durations and levels?

Thanks in advance!

 

[GregLocock]

As a rule of thumb damage is proportional to number of cycles *stress^X


X is a function of many things but 4-6 is typical. So taking X=5, your current design is good for 2*10^5. Your customer wants 0.5*50^5, a vast increase roughly 800 times as much damage.

Cheers

Greg Locock


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