×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Max displacements on a square vessel

Max displacements on a square vessel

Max displacements on a square vessel

(OP)
Well, i'm new in this forum & and i'd like to ask some advice about the design of a square vessel.
This recipient normally doesn't work under pressure but i'll be submitted to 1psi test pressure. I'm running some simulations with a FEA program & i'd like to know which could be the allowable max displacement in the flat roof, 1/100 or 1/200?
Thanks in advance
 

RE: Max displacements on a square vessel

If it's not designed to any specific code, then limitations on deflection (if any) would be at the discretion of the designer.

When using standard flat-plate formulas, one of the limitations is that deflection should be small compared to the plate thickness, or else the formulas are invalidated due to the plate acting in tension rather than just in bending.  You would need to confirm if this was an issue in your analysis as well.

RE: Max displacements on a square vessel

I agree with JStephen on the deflection should be small in relation to the wall thickness.

In the ASCE 7-05 Commentary, it mentions L/360 as the historical allowable deflection for roofs subject to full live load.  This is the criteria I typically design to.

Also, the Pressure Vessel Handbook 12th Edition by Megyesy has some great information on rectangular vessels.

RE: Max displacements on a square vessel

(OP)
Thanks JStephen and fegenbush!
Just in order to complete the info if someone needs, yesterday i was taking a look to the Megyesy, the suggested maximal allowable displacement for rectangular vessel is L/500 (length over 500), with L the maximal plate length.

RE: Max displacements on a square vessel

Just to clarify- the reason for the small-deflection criteria in many cases is because the design methods used in those cases assumed small deflections to simply the calculation.  You may have applications where huge deflections are fine- a trampoline comes to mind- but your FEA model would need to be set up accordingly.  Also, you may have some localized yielding that would be okay for a "test" case that wouldn't be acceptable under continued use.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources