CAESARII wind load

[AmineEPPM]

Hi everyone i need to choose a wind shape factor value so i am wondering is there a guide or can some one give a hint how to choose the value of this parameter and thx in advance

 

[C2it]

Check the design Code you are working to. The shape factor will usually be around 0.6 to 0.7 unless you are dealing with blast loads.

 

[DSB123]

C2it,
Agree with you value but on the Project I am on the value is dictated as being 0.5 (for wind), which I beleive is too low, and 0.7 (below 12"nb) or 1.2 (12" and above) for Blast.

 

[AmineEPPM]

I am working with ASME B31.3 and i just can't find the paragraph that describe the wind shape factor. Besides i have found in Version 5.10 CAESAR II Technical Reference Manual that a value of 0.5 to 0.65 is typically used for cylindrical sections.yet in some old project i found that the factor chosen were 0.75.
Guess i ll just stick with 0.6.

 

[DSB123]

AmineEPPM,
You should have a sound basis for your selection of the shape factor not just "Guess I'll just stick with 0.6"!!!

 

[Pipingtop]

Wind shape factor of 0.6 would be minimum. If you are unsure then use 1.0 which would give you higher wind pressures acting on the pipe and therefore occasional loads will be higher in your output.

 

[C2it]

B31.3 deals with stress limitation due to wind loads but does not address source of the load. Your project Basis of Design must specify this, so perhaps have a word with your Civil / Structural guys, they must need the same data.