CBUSH or RBE2 for BOLT ?
CBUSH or RBE2 for BOLT ?
(OP)
I'm modelling a wing with longitudinal spar and transv ribs
For the flange rib/skin bolted joint I don't know if it's better to use:
1) the CBUSH (PBUSH: K1,K2,K3,K4,K5 high and K6=0 with 3 normal to PSHELL)
2) the RBE2at each fastener location
I have seen same model with solution 1 and same model with solution 2, may you explain the differences? which is more correct?
thanks
For the flange rib/skin bolted joint I don't know if it's better to use:
1) the CBUSH (PBUSH: K1,K2,K3,K4,K5 high and K6=0 with 3 normal to PSHELL)
2) the RBE2at each fastener location
I have seen same model with solution 1 and same model with solution 2, may you explain the differences? which is more correct?
thanks





RE: CBUSH or RBE2 for BOLT ?
If you do decide to put in PBUSHes be careful not to put in an unrealistically large stiffness in any direction. This can cause numerical problems, with the symptom of causing large factor/diagonal ratio warning messages. Also, if the elements that the BUSH connects do not have any rotational stiffness out of plane you can also get numerical problems due to the BUSH "rotating".
RE: CBUSH or RBE2 for BOLT ?
Neither is more correct, thats why as an engineer you paid to determine which is more accurate for your real life situation.
RE: CBUSH or RBE2 for BOLT ?
If you really don't have any experience with this type of modeling, you should run some simple joint models using various modeling approaches and compare the results to classical load share analysis results. Then run a simplified version of a wing model using several modeling approaches and compare the results to each other and to results from classical "hand" calculations.