×
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

Wind Load/ Shape Factor For Circular Steel Tanks

Wind Load/ Shape Factor For Circular Steel Tanks

Wind Load/ Shape Factor For Circular Steel Tanks

(OP)
Hello,
Working to British Standard BS6399 does anyone know a good shape factor to use for a circular steel tank 13.8m diameter?
I've calculated my dynamic pressure qs to be 1.13kPa. Once I have applied a shape factor, over what area do i apply this?
Please Help!
thanks
John   

RE: Wind Load/ Shape Factor For Circular Steel Tanks

If the British use metric units, then why is what Americans use called English units?

RE: Wind Load/ Shape Factor For Circular Steel Tanks

In the older US tank standards, wind load on a cylinder was taken as 60% of that on a flat surface, with the load being applied to the projected area.  In the current ASCE 7, wind loading varies depending on shape and roughness of the surface, with roughness being undefined for actual tanks.

In the current API-650, that load is applied, but also uplift on the roof is used as well.  But also, load combinations have been revised, and some allowance made for the fact that tanks are seldom completely empty.

It helps if the wind loading and the overturning criteria are all taken from the same standards.

RE: Wind Load/ Shape Factor For Circular Steel Tanks

Only Americans call them English units.

The correct term is Imperial units.

RE: Wind Load/ Shape Factor For Circular Steel Tanks

(OP)
Thanks Apsix and JSteven, your advide has been pretty helpful. I also continued the search myself yestered and evenetually found the answere in the Britich design Code 6399. Section 2.4.6 is for wind loading to Circular Plan buildings including silo's Tanks stack and chimneys. It uses Table 7 indicating varying pressure given the winds position on the periphery. It is very similar to the graph in the OZ code apsix.

Thanks for your help peeps! Great forum, its the first time i've used it. i'm sure i'll be back.

RE: Wind Load/ Shape Factor For Circular Steel Tanks

I live in a non-seismic area but seismic has always governed my design for cylindrical water/fuel tanks. For wind load, I have taken the cylinder tank as a box-shape. I would think the cylindrical shape of the tank makes it more aerodynamic (ie. less wind load.) so my assumption would be conservative. Someone correct me if I'm wrong.

Clansman

If a builder has built a house for a man and has not made his work sound, and the house which he has built has fallen down and so caused the death of the householder, that builder shall be put to death." Code of Hammurabi, c.2040 B.C.

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