Hello,
I have a project with a truss that has 3 scissor joints.
This is my first time using it, and I think I made a mistake. I placed a joint on 2 of the 4 bars in the assembly.
Ferme 2 appuis R0 Cl2.rf6 (1.4 MB)
I checked it using moment transfer, and I think I have a problem with the two upper scissors.
Hello @Massimo,
The error was in the released degrees of freedom. In the joint’s “Base” tab, you checked the uX and uZ translations, while the φY rotation remained restrained. This produces the opposite of the intended effect: the node no longer transmits the normal or shear forces, but still transmits the moment from one pair to the other. This explains the discontinuous values you observed on the two scissors.
The correction:
• uncheck uX and uZ, and check φY
• enable the “Scissors joint” option and, in the “Scissors joint” tab, check only φY
->Only the normal and shear forces will be transmitted.
Attached is a comparison of the My moments at the upper-right scissors joint: the corrected model is on the left, and your initial model is on the right. In this area, the maximum decreases from 20 to 10 daNm. Most importantly, the raised tie (59-62) and the diagonal (50-61) are now each continuous as they pass through the node, with no transfer of moment from one to the other.
Best regards,
Hedi Boukraa
