Menu

Discussion Forum

New Discussion
Filtern

Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Variable time stepping

Posted 08.03.2012, 04:30 GMT-5 Studies & Solvers Version 4.3a 3 Replies

Tesfaye Tadesse Molla
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi

Would you help/suggest me on how to set up a variable time stepping scheme in a time dependent solver ( COMSOL 4.2a)

Thanking you in advance
3 Replies Last Post 06.11.2014, 20:21 GMT-5
Wiktor Stenström
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 08.03.2012, 04:45 GMT-5
Hi Tesfaye,

I assume you use a "Time Dependent" study/solver and want to use a variable step size. COMSOL automatically determines (and varies) the needed time step to meet your prescribed tolerances. What you can control is the maximum allowed size of the time step and also whether the steps should be free (where the solver completely disregard the time increments specified where you define the study step), intermediate (where the solver at least makes one computation between two time increments you specify) and strict (where the solver always calculates at the specified times but can take steps inbetween if needed). This is described further in the documentation.

Wiktor


------------------------------
Master student at KTH, Stockholm
Independent consultant in structural analysis
www.wiktorstenstrom.se
Hi Tesfaye, I assume you use a "Time Dependent" study/solver and want to use a variable step size. COMSOL automatically determines (and varies) the needed time step to meet your prescribed tolerances. What you can control is the maximum allowed size of the time step and also whether the steps should be free (where the solver completely disregard the time increments specified where you define the study step), intermediate (where the solver at least makes one computation between two time increments you specify) and strict (where the solver always calculates at the specified times but can take steps inbetween if needed). This is described further in the documentation. Wiktor ------------------------------ Master student at KTH, Stockholm Independent consultant in structural analysis http://www.wiktorstenstrom.se
Tesfaye Tadesse Molla
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 08.03.2012, 08:17 GMT-5
Thanks Wiktor,

It seems working now.

Would you have any idea/suggestion on how to mesh very thin layer (27micro meters) interface to a thick layer (400 micrometers) in solid mechanics module as a domain ( i would like to define few domain based deformation parametrs) and have a converging solution ???

I am struggling with such problem and cant get a converging solution or it takes very long time for comsol to run (ofcourse with time dependent solver)

Thanks once again for your suggestions
-Tesfaye
Thanks Wiktor, It seems working now. Would you have any idea/suggestion on how to mesh very thin layer (27micro meters) interface to a thick layer (400 micrometers) in solid mechanics module as a domain ( i would like to define few domain based deformation parametrs) and have a converging solution ??? I am struggling with such problem and cant get a converging solution or it takes very long time for comsol to run (ofcourse with time dependent solver) Thanks once again for your suggestions -Tesfaye
Letian Wang
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 06.11.2014, 20:21 GMT-5
Hi Tesfaye!

I am also looking for variable time stepping, so could you tell me how to do that?

Thanks!

Letian


Thanks Wiktor,

It seems working now.

Would you have any idea/suggestion on how to mesh very thin layer (27micro meters) interface to a thick layer (400 micrometers) in solid mechanics module as a domain ( i would like to define few domain based deformation parametrs) and have a converging solution ???

I am struggling with such problem and cant get a converging solution or it takes very long time for comsol to run (ofcourse with time dependent solver)

Thanks once again for your suggestions
-Tesfaye


Hi Tesfaye! I am also looking for variable time stepping, so could you tell me how to do that? Thanks! Letian [QUOTE] Thanks Wiktor, It seems working now. Would you have any idea/suggestion on how to mesh very thin layer (27micro meters) interface to a thick layer (400 micrometers) in solid mechanics module as a domain ( i would like to define few domain based deformation parametrs) and have a converging solution ??? I am struggling with such problem and cant get a converging solution or it takes very long time for comsol to run (ofcourse with time dependent solver) Thanks once again for your suggestions -Tesfaye [/QUOTE]

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content