Hi all,

I'm currently working on existing flowlines with existing constant spring hangers in the system. I would like to know how to correctly model a pre-defined constant spring hanger using YSPR. I have read the CII manual but when i apply it, the results doesn't make sense. In my system, i have a constant spring hanger with total travel of 368mm and load of 25000 N. In the Restraint field, my "x" is 368mm and my F is 25000 but i leave a blank for 'Stif' since it is a constant spring hanger. However, after running the analysis, my displacement is 0 in Y direction and it happens to all my spring hangers. I don't think all my spring hangers bottom out. Please advice where did i do wrong

"Stif" needs to be zero for constant (i.e. no variation in load).

Blank mean rigid hanger.

Regards,

What you have is not really a "restraint" in CAESAR II. Restraints define a stiffness. A hanger provides stiffness and/or load. It's the load you want. Don't call it a restraint. Instead, define a hanger at the node and use the bottom of the hanger auxiliary data area. There you can define the constant hanger load. For a constant you need not enter a stiffness.

Indeed, but since he want the "bottom out" feature, this is the metod what Caesar reccomend. Isn't it?

Oh, right.
Then, yes, your point of not leaving stiffness blank is what's important here. But I wouldn't use zero; I'd use 1. (I never tried zero.)