To ALl,
I am working on a flare line. There are approximately more than 40 pipe supports. When i enter friction factor Mu: 0.300 for steel to steel and than run my analysis. The system never converge and the iteration keeps going.

Is there any setting I need to change to make the system converge with the friction factor Mu: 0.300

Thank for your help..

Use the "search" - convergence. You will find some usefull techniques.

Regards,

For convergence, you can change the friction stiffness values in the "Configuration file".

The three factors related to the non-convergence is guide gap, uplift of pipe and friction coefficient. If the above said friction stiffnes not helping, you can try in adjusting the other three (be caution in using these three factors) for the convergence.

Change the friction stiffness in TOOLS/CONFIGURE SETUP and run the system.
Still its not converging decrease the stiffness value more once again...
After converging check the displacements at supports which is lifting. Note down the nodes and replace the original stiffness value & run the system. The system doesnt converge now go to the restraint nodes which you noted and try to decrease the friction value. Instead of 0.3 give 0.2 and still it is not converging make friction value 0 at that particular nodes.
Definately the system ill converge. Practically the friction is not same at every support. As time varies the friction at support varies due to climatical condition. So dont bother...
But dont change the stiffness value in TOOLS, where it shows less allowable loads at battery limits.

Or search in forum for "convergence problems". You ill find usefull information.

Regards
Kollapaneni

Hi Kollapaneni,

Changing the friction stiffness in the TOOLS/configure set up will have much impact on nozzle loads as said .Can u just explain me on what basis the friction value at support changes as time varies due to climatic conditions.
As we all know, changing the friction value will improve convergence, also horizontal forces due to guide or cross guide get reduced.But I came across one thing that the forces due to +y restraint also get reduced after changing the friction value.Is this is acceptable or not.

If the support will not lift-off for the OPE and SUS cases, then USE a "Y" NOT a "+Y". This will help Caesar II converge. Search and read more posts. I stongly recommend that you DO NOT MESS with the friction stiffness etc...