Bolted Flanged Connection

[kayeng]

I have a bolted flange connection that is not in a pressure situation. It is basically a connection in a pipe that is used as a spreader bar. It has a particular moment and shear at the point of the flange. My questions are:
1. Do I use the specific recommended torque for the size of the bolt or do I base it on my calculated stress in the bolt?
2. How do I assume how the load is distributed compression and tension throughout the bolt pattern? I would like to assume half compression, half tension, but I know that is not true.

Thank you in advance for your help.

 

[arto]

for #2 there's a Bracket analysis in Grandpa's Maleev Machine Design Book (Scranton PA: Int'l Textbook Co. 1946) pg125

It assumes pivot @ the bottom edge [i.e., shear on lip - not the bolts]
Bolt Force Fi = M*Li/[L1^2 + L2^2 +L3^2 +......]

M = moment
L1 = distance from pivot to Bolt 1 cL, etc.

 

[UcfSE]

2 You could probably do an elastic analysis on the bolt group for eccentric loading to find the force in each bolt due to the moment and hence the highest force in a bolt. Elastic analyses are common for structural eccentrically loaded connections and are usually conservative.

1 ? What is "it"? Your question isn't clear.

 

[kayeng]

Thank you very much for your responses.

It was the torque value. I would assume that it is good practice to create a preload that is equal to or greater than any tensile force the bolt would see in use.