HI. Thanks for the detailed explanation, I will definitely try it! Since you mentioned the problem of the Direction of the stiffness problem, do you think it is the reason the solution failed when the connection was not Bonded? SInce only when Bonded, the beam would have all 6 directions of stiffness taken care of (since all 6 are fixed). And after I generate a No Separation, how do I make the beam have the same dimension as the ID of the tube?

On the other hand, do you know what's the issue with Normal Lagrange that I can't use it? Thanks a lot!