Bolt Mounting Plate Gypsum

[Mandrill22]

I haven't done any calcs with gypsum before. How would I calculate the max shear that a 1/4-20 bolt (could be grade 9 steel) could take, when holding up a ss mounting plate of 9.5mm thickness? The plate will be agains 5/8 gypsum with a clearance hole for the bolt. The bolts go into rivet nuts in 1mm steel studs. The reaction forces at the plate are below.

Also, is the shear load on the rivet nut different than the reaction shear load?

 

[phamENG]

Ignore the gyp. Look at bending in the fastener. The fastener will be a lot stiffer than the bearing capacity of some drywall - even the heavy duty exterior stuff. The fastener will be "fixed" in the rivet nut at the stud, cantilever the thickness of the drywall, and be loaded by your plate.

 

[Mandrill22]

Is the von mises stress the right way to go?