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local shell stresses from pad/lug/leg welded to shell?

local shell stresses from pad/lug/leg welded to shell?

local shell stresses from pad/lug/leg welded to shell?

(OP)
Hi,
I am looking into putting legs onto the cylindrical shell of a vertical vessel. My understanding is that the vessel will not fall under ASME codes, because it will be pressurized to a maximum of 1.3 bar (absolute) during operation.

There will be reinforcing pads attached to the cylindrical shell by welding the reinforcing pads around their perimeters onto the shell; then, lugs will be welded to the reinforcing pads; finally, legs will be welded to the lugs.

My question is, how should I approach the analysis of local stresses within the cylindrical shell due to horizontal loading on the shell/pad/lug/legs?

The horizontal loading is from ASCE-7 seismic loads.

In the handbook by Megyesy, there is a section regarding analysis of shell stresses due to vertical loads acting on pads/lugs; can that be adapted to horizontal loads?

I have heard of a WRC 107 bulletin, but I am looking for an alternative resource, before shelling out ~300$ to access WRC 107.

Any help/advice appreciated

RE: local shell stresses from pad/lug/leg welded to shell?

What are the horizontal loadings on these lugs coming from?

It appears to me that you got a vertical load (the vertical PV) being supported from below by a small cantilever of the vertical legs-lugs-pads offset, but that's all.   Are you thinking of his (Megyese's) horizontal loads from wind/seismic conditions?   

RE: local shell stresses from pad/lug/leg welded to shell?

(OP)
hi racookpe1978,

The horizontal loadings are seismic design forces from section 13.3.1 of ASCE 7-10
(see: http://books.google.ca/books?id=i1TOe5chZJQC&printsec=frontcover&dq=asce+7-10&hl=en&ei=LSeyTenwDIiCsQPWhtTrCw&sa=X&oi=book_result&ct=result&resnum=1&ved=0CE8Q6AEwAA#v=onepage&q=asce%207-10&f=false)

Although Megyesy, and Moss's books have methods for analyzing horizontal loads on lugs and legs, I am looking for methods to analyze horizontal local loads applied to the shell itself, in addition to the pressure and vertical loads (weight) already acting on the shell.

RE: local shell stresses from pad/lug/leg welded to shell?

Have a look at API-650 Appendix P.

Welded Steel Tanks for Oil Storage - APPENDIX P—ALLOWABLE EXTERNAL LOADS ON TANK SHELL OPENINGS

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