effect of (a circular) plate stiffness on bolt load distribution?
effect of (a circular) plate stiffness on bolt load distribution?
(OP)
To all
I am looking for info on the effect of stiffness/flexibility on bolt load distribution for a ring-type of plate. Consider the following
A part like a flange (diameter D, thickness t) with N bolt on a PCD d so that d < D. A basic load balance at the CofG of the bolt group produces a (shear) force Fs and a Moment M. A simple calc would say the shear force per bolt = Fs / N. The tensile load in each bolt produced by M is calculated by any traditional method. So far so good
I now have a FE model with which I can extract the force on each bolt. The force Fs and moment M transmitted by the FEM appears to be correct (as expected) but the load distribution is nowhere near the simple hand calc.
Is this because of the flexibility of the plate? If so then how does one take this into account in a "simple" hand calc?
Thanks
Regards
I am looking for info on the effect of stiffness/flexibility on bolt load distribution for a ring-type of plate. Consider the following
A part like a flange (diameter D, thickness t) with N bolt on a PCD d so that d < D. A basic load balance at the CofG of the bolt group produces a (shear) force Fs and a Moment M. A simple calc would say the shear force per bolt = Fs / N. The tensile load in each bolt produced by M is calculated by any traditional method. So far so good
I now have a FE model with which I can extract the force on each bolt. The force Fs and moment M transmitted by the FEM appears to be correct (as expected) but the load distribution is nowhere near the simple hand calc.
Is this because of the flexibility of the plate? If so then how does one take this into account in a "simple" hand calc?
Thanks
Regards






RE: effect of (a circular) plate stiffness on bolt load distribution?
Where did you get the "simple" hand calc method for circular plates? Because there are multiple different methods you could use.
Have you read Dan Horn / TnxTower's Technical manual about the design of Monopole Bases? That's a really good reference for this subject.
RE: effect of (a circular) plate stiffness on bolt load distribution?
RE: effect of (a circular) plate stiffness on bolt load distribution?
What I meant about the simple calc. refered to a traditional way of checking a bolt group subjected to moments (one of them being a overturning moment)
Found the pdf of the suggestion reference
RE: effect of (a circular) plate stiffness on bolt load distribution?
how is the FEM deflecting ? is the flange very flexible so the loading structure can pull away from the tension loads (off-loading the peak tension fasteners) ?
another day in paradise, or is paradise one day closer ?
RE: effect of (a circular) plate stiffness on bolt load distribution?
Deflection a in line with one what expect and appears quite reasonable
One can describe the base plate/flange as very chunky but it is carrying a fair load.
As 1st pass I'll interested to know why the shear force/bolt is higher than the simple Fs/N.
RE: effect of (a circular) plate stiffness on bolt load distribution?