Bolt loads for beam rigidly connected to overhead support

[bsmet95]

I must support a load with a beam as per the attachment. There are two pairs of bolts at each end. This appears to be a statically indeterminate situation for bolt reaction calc's. is there a way to determine or estimate the tensile load in each pair of bolts?

Thanks.

 

[desertfox]

hi bsmet95

I assumed the beam to be ridged and took moments from one end of the beam. In addition I assumed a unknown bolt load per unit length and called it µ, so each bolt pair was given a length from one end of the beam i.e. la, lb, lc ld.

la=1.5
lb=5
lc=54.25
ld=57.75

My equation ended up looking like this:-

15000*59.25"/2 = µ*2* (la^2 + lb^2 + lc^2 + ld^2)

solve for µ

µ= 35.25

so the maximum bolt load occurs at 57.75 therefore 57.75*35.25 = 2035.6875
now for a pair of bolts at 57.75 then the force is doubled to 4071.375 and the next nearest pair at 54.25 would be 3824.625.

So because the beams symmetrical I ignored the bolt forces close the the pivot where I took moments and considered the pair of forces I calculated above to check for equilibrium

ie forces at each end of beam = 3824.625 + 4071.375 = 7896

so if I double this I get 15792

upward forces = downward forces 15792=15000 well not quite but a 5% error is acceptable to me and it also agrees pretty closely with just dividing the total downward force by the number of bolts.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein