Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Seismic Calculations in Compress Without Supports 1

Status
Not open for further replies.

withak36301

Mechanical
Aug 28, 2009
12
US
Am designing a low-pressure vessel that will have a flat bottom head anchored to a concrete pad, and need to evaluate for seismic effects. Is there any way to get a seismic code report without putting in a support system?
Yes, I realize this is more an API 650 situation but we're still designing to ASME VIII. Please advise.
 
Replies continue below

Recommended for you

Did you try making the bottom a welded flat and attach the lugs to the shell? You will undoubtedly fail the bottom but it may work. Is the tank/vessel mechanically or self-anchored?

Why don't you simply write a spreadsheet or do hand calculations? I strongly dislike the type of work around I wrote above; it seems like forcing the program to do something it isn't necessarily meant to do. Why don't you use the building code requirements which will likely direct you to an API 650 or similar methodology (depending on where you are)?

Compress, PVElite, etc. are great for getting you most of the way there and sometimes other means are needed to finalize or at least verify the result. Also, for the attachment (if you are using ASCE 7) see if you need to include the over strength factor Ω; the last time I checked Compress didn't included it. Normally I design the lugs/chairs/etc. outside of Compress so i don't typically look in the support calculations.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Top