[petsc-users] Staggered solver phase field

[PERRIER-MICHON Augustin]

Dear Mr Smith,

Thank you for your answer.

Maybe I do not understand your interrogation because I am not familiar 
with fluid flow simulations. Each physics are solved on an entire time 
step at every time step.
This is a quasi static problem with an incremental loading. Later I will 
add time dependent phenomena thus I chose TS solver.

Thanks
Augustin

Le 2025-04-23 17:38, Barry Smith a écrit :
> I am unfamiliar with this simulation type, so I have some elementary
> questions. Is each "physics" taking a fractional time-step so that the
> total time
> integrated (in a time-step) is 1/2dt + 1/2dt or is one physics
> stepping the entire time-step and the other physics "fixing up some of
> the variables" (for example, in fluid flow where a pressure solve
> doesn't step in time it merely changes some variables values to
> enforce incompressibility at the new time). Another way to phrase the
> question is are the underlying equations a DAE, not an ODE?
> 
>   Barry
> 
> 
>> On Apr 23, 2025, at 10:20 AM, PERRIER-MICHON Augustin 
>> <augustin.perrier-michon at ensma.fr> wrote:
>> 
>> Dear Petsc users,
>> 
>> I am currently dealing with finite element fracture analysis using 
>> phase field model. To perform such simulations, I have to develop a 
>> staggered solver : mechanical problem is solved at constant damage and 
>> damage problem is solved at constant displacement.
>> 
>> I created 2 TS solver and 2 DMPLEX for each "physics".
>> Each physics's system is built using TSSetIFunction and TSSetIJacobian 
>> with associated functions.
>> 
>> The TS calls are performed with TSSTEP in order to respect staggered 
>> solver scheme in iterative loops.
>> 
>> My question : Is the using of TSSTEP function adapted to a staggered 
>> solver ? How to use this function in my framework ? Have you got any 
>> other suggestions or advices ?
>> 
>> Thanks a lot
>> Best regards
>> 
>> --
>> Augustin PERRIER-MICHON
>> PhD student institut PPRIME
>> Physics and Mechanics of materials department
>> ISAE-ENSMA
>> Téléport 2
>> 1 Avenue Clément ADER
>> 86361 Chasseneuil du Poitou- Futuroscope
>> Tel : +33-(0)-5-49-49-80-97