Fastener joint modeling using single RBE2 instead of CBUSH w/ "spider" RBE2
Fastener joint modeling using single RBE2 instead of CBUSH w/ "spider" RBE2
(OP)
Hello,
I have a question I was hoping you all could answer. A coworker sent me an FE model that he created, where he modeled a bolted joint using just an RBE2 element (with DOFs in 123) to connect the matching holes in 2 plates. I would never do this; my preferred modeling method would be to add a CBUSH element between the two holes and then connect each end to their respective plate with an RBE2.
Is it even possible to extract usable MPC forces from my coworker's model? When I plot the MPC forces marker, I get 0 lbf in every direction. Is this due to the summation of forces at the independent node or something? I know that RBE2s are infinitely stiff, so I suspect any forces/stresses at this type of joint wouldn't even be realistic or worth assessing.
I've attached a picture of a quick FEA mockup of a joint with just an RBE2 vs my preferred method of a CBUSH w/ RBE2s.
Thanks for the input!
I have a question I was hoping you all could answer. A coworker sent me an FE model that he created, where he modeled a bolted joint using just an RBE2 element (with DOFs in 123) to connect the matching holes in 2 plates. I would never do this; my preferred modeling method would be to add a CBUSH element between the two holes and then connect each end to their respective plate with an RBE2.
Is it even possible to extract usable MPC forces from my coworker's model? When I plot the MPC forces marker, I get 0 lbf in every direction. Is this due to the summation of forces at the independent node or something? I know that RBE2s are infinitely stiff, so I suspect any forces/stresses at this type of joint wouldn't even be realistic or worth assessing.
I've attached a picture of a quick FEA mockup of a joint with just an RBE2 vs my preferred method of a CBUSH w/ RBE2s.

Thanks for the input!
RE: Fastener joint modeling using single RBE2 instead of CBUSH w/ "spider" RBE2
RE: Fastener joint modeling using single RBE2 instead of CBUSH w/ "spider" RBE2
RE: Fastener joint modeling using single RBE2 instead of CBUSH w/ "spider" RBE2
RE: Fastener joint modeling using single RBE2 instead of CBUSH w/ "spider" RBE2
"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.
RE: Fastener joint modeling using single RBE2 instead of CBUSH w/ "spider" RBE2
RE: Fastener joint modeling using single RBE2 instead of CBUSH w/ "spider" RBE2
RE: Fastener joint modeling using single RBE2 instead of CBUSH w/ "spider" RBE2
if you are doing a 2D model, mesh as you like and use element results (shear/in) to derive fastener loads.
obviously use more attention for discrete high load fasteners (wing attach) than "ordinary" skin/frame of skin/stringer rivets.
"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.
RE: Fastener joint modeling using single RBE2 instead of CBUSH w/ "spider" RBE2
RE: Fastener joint modeling using single RBE2 instead of CBUSH w/ "spider" RBE2
"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.
RE: Fastener joint modeling using single RBE2 instead of CBUSH w/ "spider" RBE2
RE: Fastener joint modeling using single RBE2 instead of CBUSH w/ "spider" RBE2
eg a skin splice between two elements may be directly Fxy, from FE output.
shear flow into a frame cap (or shear splice) may require some additional element addition/subtraction.
then what is the typical rivet spacing
and so the typical rivet load = (load/in)/(rivets/in)
"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.