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Seismic / Transportation acceleration values

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NickParker

Electrical
Sep 1, 2017
446
We have an equipment, that is battery rack with batteries. The below values of Seismic / transport acceleration values are given by my structural team.

Acceleration_Values_adombl.png


The Battery vendor says, he is complying to 0.6g. Is that acceptable? as there is no mention of vertical heave compliance from the vendor.

I tend to think that it is acceptable, since it is the highest value (read it as worst case scenario).

Any advise?
 
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I think the former seismic vertical acceleration is more important for foundation/connection design, and the latter is for determine fastening method and tie-down force of the equipment during transportation. I've difficulty to connect the vertical accelerations to the design of skid, unless the equipment is to be rigidly connected to the skid.
 
I agree with retired13, the verticle would be necessary for connection design.

You can run a static analysis and determine the expected vertical seismic force. Then, determine the equilibrium force and see (gravity - seismic) and see if your connections are adequate.


One critical case scenario would be if the seismic force overcomes the gravity forces, and you get tensile stresses on simply supported members and connections.
 
During transportation, you can always temporarily brace the component against those forces.
 
NickParker:
“The Battery vendor says, he is complying to 0.6g.” Just add to that, in all capital letters and red color “in all directions, and under all modes of transportation,” and send it back to him, as your understanding of his intent, and for the records. Your own company should check that that is adequate for all possible modes of transport which might be used, and that that meets the local EQ code requirements. Some modes of transport are more abusive to hauled equipment than other modes. And, you can put accelerometers on the equipment to keep all handling parties honest, if you wish.
 
Is there some reason you didn't just ask the vendor and/or your structural team? Is the vendor supplying the entire skid and batteries?

But, the answer your specific question is "no." You have separate requirements and you need to have your "structural team" to step up and provide a more detailed and specific requirement

> quasi-static "seismic" -- you need to get clarification from your structural team whether this is treated as purely static loads or whether there is frequency dependence
> horizontal acceleration -- what is your structural team's requirement for frequency content?
> vertical "heave" -- again, what is your structural team's requirement for frequency content?

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
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