saddle reaction force factor 4

[lbela]

Would anyone give me an answer if I can go lower then recommended value of 3 (saddle reaction force factor)
when calculating saddle reaction force?

 

[TomBarsh]

Where does this force factor exist? Is this in a stress calculation in the shell? Or is this a force on anchor bolts, etc? The details of all this matter very much.

 

[lbela]

I better say "when calculating saddle reaction force due to transverse wind or seismic forces".
I am using Code Calc, PVElite to design saddles for horizontal vessel.

 

[TomBarsh]

You may be better off posing this question directly to Coade (publishers of Code Calc and PVElite). Contact them at support "at" coade.com or try their forum at

http://www.coade.com.

 

[lbela]

Thank you for the effort to help me out.

 

[gr2vessels]

lbela,
You seems to be offended by the replies;- it was not intended any offence. Your original post was confusing, and the your reply was perhaps very specific for most of PV designers.
The "value" used in Moss manual is 6 with no alternatives;- Coade took a step forward and calculated the traverse load located at the edge of the base plate, rather than uniformly distributed. This allowed the reduction of the "value" down to 3. That's the minimum. Please note that you can use only 3 or 6, it doesn't work with 5.37 or other decimals.
cheers,
gr2vessels

 

[saplanti]

Ibela,

Some years ago I had similar discussion with Coade.

Since the discussion was very educational, I attached it here without getting Coade's permission and I hope they do not mind.

The basic on the saddle reaction factor is in the calculation of columns with foundation. You may need to look at AISC guide books or Blodgett’s Design of Weldments for this kind of design.
The saddle behavior changes with the bolt application under the large horizontal loads. Sometimes you do not need uplift bolts due to the low horizontal force which can not overturn the vessel. Some case designers use local friction pads under the saddle and elevate the saddle from foundation. In this case the behavior is completely different. In case you use the friction pad in full length of the saddle you can use bearing reaction to restrain against overturn by the use of shear keys etc…

Everything depends on your selection of saddle supporting type.
Therefore, you need to know what you are doing before the use of the programs. Sometimes, some of the application I described above was not supported by the programs.

Kind regards,

Ibrahim Demir

 

[lbela]

Thank you everyone