Hi every specialist;

I have two following questions:
1) Can you explain in which practical cases we shall consider “Post Yield Stiffness “ as rigid (K2=0)?
2) Using Caesar II, by default this K2=1 not equal to "0" for buried pipeline. Is there any quick procedure in order to set this K2=0 not by typewriting 0 for each piping segment?

Many thanks

Where are U specialist?

I need your help...Please don't forget my thread....

You can't have a stiffness of zero, hence the value of 1.

Richard;

Please see attachment where it is clearly specified that in some cases we can set K2=0. K2 is the post yield stiffness.
I found out that some engineers set K2=0 for above ground pipeline.
Is it a correct way to model a surface pipeline?

What attachment?

Analytically, you shouldn't use a stiffness of zero, what happens when the solution attempts to divide by this value ? (Try it on your calculator, CAESAR II will do the same thing.)

I have no idea how to model a pipeline sitting on the ground. I believe I've stated this elsewhere. The theory used in CAESAR II assumes the pipe is buried. If that is not the case, then the assumptions and equations used in the Buried Pipe Modeler are not applciable. Therefore, the re-meshing performed and the resulting restraint stiffnesses would also not be applicable.