eccentric circular bolt loads

[femengr41]

I have a circular pattern of bolts. One bolt in the pattern is missing. Given a single shear load aligned between any two bolts at "x" inches away from the shear plane.....What's a good method of finding bolt shear and tension on each bolt?

 

[WillisV]

Is there a grout pad under a baseplate or just bolts?

 

[diamondjim]

Just curious about the number of bolts
in the full circle. The one missing
bolt has little effect if you have
many bolts in the pattern. I think
I still have a method that was used
for segmented bolt patterns lying around
my office somewhere. Is the shear
about one of the neutral axis or across
the full circle pattern? Do you have
moment loading as well as radial
and axial loading?

 

[femengr41]

This is a 4 bollard situation lifting a heavy machine. 7 bolts with a space at the 8th top position. Bollard is loaded with dead load and a cable load off at a variable angle. Moment arm is 4 to 5 inches off the bolt shear plane. No grout but steel to steel contact. Bolts may be pre-loaded. No radial loads to create direct bolt tension.

femengr41

 

[femengr41]

no grout.... this is steel bollard to steel machine base situation. femengr41

 

[arto]

plan on only 2 diagonal bollards taking the load.
Bolts in shear or friction is not ideal - should be a lip or dowel to take the shear.
Maleev's Machine Design p.124 has a section on calculating bracket bolt patterns like this.

 

[Heckler]

I second arto on bolts taking a shear load. In eccentric loaded connections it would be in your best interest to run the numbers to see how each bolt is loaded. Examples of how to calculate this can be found in any undergrad mechanics book.