yeah, I see it now. Whats your opinion of what i should do? If i added a Support in node 1 (RX, RY and RZ) i get as good as zero. Would this be the proper way of doing it?
After we put the soft springs in each of the four corners we still get a wierd reading in the displacements bar under node properties.
as I said before " your lifting point coordinates (node 71) should be as precise as the CG of the loads on your lifting load case/combination"
This will not work with several load cases.For each load case you should have a unique lifting support type(UX + coordinates) according to the lifting point coordinates.
If the lifting point coordinates doesn´t match the Loads CG , the sum of the cables horizontal components will not be zero and as consequence you´ll get horizontal reactions on the XY supports and large displacements on the structure nodes
I just wonderd if modelling the cables, lifting the construction, would work but only modelling them half way to there meeting point ( center of gravity) or so and placing a support there for every cable. Then you would get 4 pin supports, and realistic force distribution in your structure with x, y and z forces acting on the corners....
Just downloaded the model and playd with it a little. I did have to place fixed supports at the end og the cables, forcing them to get some moments but placed an release at the connection to the main struture so that the moments wont travel further into the structure. I have not been using Robot for a long time so this may be total fail but this way I think the axial forces from the cables with there angle towards center of gravity will be taken into account without playing with supports at each corner