Shear on bolts/pins in rotational system 1

[Tigerdawg]

I have a system of two rotating disks fastened with bolts and pins. Due to the difficulty of removing these bolts and pins, I want to ensure they do not fail before the locking device on the shaft fails.
How would I calculate the stress on the bolts if the system is under a 'sudden impact' that immediately stops the disks from rotating? I'm aware of a way to determine the stresses/deflections in the shaft, but is there a way to relate this to the fasteners on the disks?

 

[ivymike]

I'd start by calculating the peak torsional load in the joint due to the sudden stop.

Next, I'd perform a bolted-joint calculation to see what sort of clamp load was available at the joint. I'd look at the fastener spec and tightening spec (perhaps 80% yield in the fasteners, depending on how they're torqued).

After that, I'd try to estimate the torque that can be transmitted via friction in the joint. It would be ideal if the friction force exceeded the peak "sudden stop" torque at the joint, because then I wouldn't have to worry about the bolts and pins.

If I wasn't that lucky, I'd start with the (pessimistic) assumption that the sudden stop torque would be entirely carried by the bolts & pins. Based on the number of fasteners and their radii, I'd estimate a shear load on each for the estimated torque. I'd compare that to the known strength properties of the fasteners, and see how they compare.

That's a summary of how I'd perform some first-cut analyses of the system you've described; more detailed approaches are available.