beam rod joint in patran

[tillo]

Hi.
I'm working for my graduation thesis on a structure analysis on patran.
I have to reconstruct the set of the tree of a sailboat in msc patran 2008 r2 and therefore I am working with elements 1d cbeam and rod.
I am having problems in the joints between beam(shaft and boma) and rod(x all steel cables) because being beams under bending the rods that I joined with mpc rbe 2 binding the translations and leaving free the rotations do not follow the deformation but I only have a deformation in the final element that does not make sense.. .
I also tried to rebuild the cables with beams with very low inertia modules but I'm not convinced.. .
What do you suggest to do to model the ropes and beam-rod joints?
Thank you.
Andrea

 

[Onda]

hi gorea, welcome to the forum, normally you should submit to the first post!
if you read the forum rules there is a procedure.

to join a crod to a cbeam you don't have to insert a rbe2, simply the crod does not bring flexions but only traction loads (and twist along the axis, to be canceled by putting a twist stiffness nothing to the element).
to join two cbeams, tree and boma or tree and crucifixes, you can eliminate the degrees of rotation to the knot of the cbeam. There is a patran flag to eliminate the degree of freedom to an extreme of the beam.
For example, at the boma beam junction node, you must eliminate ry and rz, considering that the boma is not free to rotate around itself in the trough.

Keep in mind that crods cannot be loaded with normal loads but only in traction.

wave