DAMASK_EICMD/src/DAMASK_FEM.f90

!--------------------------------------------------------------------------------------------------
!> @author Pratheek Shanthraj, Max-Planck-Institut für Eisenforschung GmbH
!> @author Martin Diehl, Max-Planck-Institut für Eisenforschung GmbH
!> @author Philip Eisenlohr, Max-Planck-Institut für Eisenforschung GmbH
!> @brief Driver controlling inner and outer load case looping of the FEM solver
!> @details doing cutbacking, forwarding in case of restart, reporting statistics, writing
!> results
!--------------------------------------------------------------------------------------------------
program DAMASK_FEM 
#include <petsc/finclude/petscsys.h>
 use PetscDM
 use prec, only: &
   pInt, &
   pReal, &
   tol_math_check
 use DAMASK_interface, only: &
   DAMASK_interface_init, &
   loadCaseFile, &
   getSolverJobName
 use IO, only: &
   IO_isBlank, &
   IO_stringPos, &
   IO_stringValue, &
   IO_floatValue, &
   IO_intValue, &
   IO_error, &
   IO_lc, &
   IO_intOut, &
   IO_warning
 use math                                                                                           ! need to include the whole module for FFTW
 use CPFEM2, only: &
   CPFEM_initAll
 use FEsolving, only: &
   restartWrite, &
   restartInc
 use numerics, only: &
   worldrank, &
   maxCutBack, &
   stagItMax
 use mesh, only: &
   mesh_Nboundaries, &
   mesh_boundaries, &   
   geomMesh
 use FEM_Utilities, only: &
   utilities_init, &
   tSolutionState, &
   tLoadCase, &
   cutBack, &
   maxFields, &
   nActiveFields, &
   FIELD_MECH_ID, &
   COMPONENT_MECH_X_ID, &
   COMPONENT_MECH_Y_ID, &
   COMPONENT_MECH_Z_ID, &
   FIELD_MECH_label
 use FEM_mech
 
 implicit none

!--------------------------------------------------------------------------------------------------
! variables related to information from load case and geom file
 integer(pInt), allocatable, dimension(:) :: chunkPos                                               ! this is longer than needed for geometry parsing
 integer(pInt) :: &
   N_def = 0_pInt                                                                                   !< # of rate of deformation specifiers found in load case file
 character(len=65536) :: &
   line

!--------------------------------------------------------------------------------------------------
! loop variables, convergence etc.
 integer(pInt), parameter :: &
   subStepFactor = 2_pInt                                                                           !< for each substep, divide the last time increment by 2.0
 real(pReal) :: &
   time = 0.0_pReal, &                                                                              !< elapsed time
   time0 = 0.0_pReal, &                                                                             !< begin of interval
   timeinc = 0.0_pReal, &                                                                           !< current time interval
   timeIncOld = 0.0_pReal, &                                                                        !< previous time interval
   remainingLoadCaseTime = 0.0_pReal                                                                !< remaining time of current load case
 logical :: &
   guess, &                                                                                         !< guess along former trajectory
   stagIterate
 integer(pInt) :: &
   i, &
   errorID, &
   cutBackLevel = 0_pInt, &                                                                         !< cut back level \f$ t = \frac{t_{inc}}{2^l} \f$
   stepFraction = 0_pInt                                                                            !< fraction of current time interval
 integer(pInt) :: &
   currentLoadcase = 0_pInt, &                                                                      !< current load case
   currentFace = 0_pInt, &
   inc, &                                                                                           !< current increment in current load case
   totalIncsCounter = 0_pInt, &                                                                     !< total # of increments
   convergedCounter = 0_pInt, &                                                                     !< # of converged increments
   notConvergedCounter = 0_pInt, &                                                                  !< # of non-converged increments
   fileUnit = 0_pInt, &                                                                             !< file unit for reading load case and writing results
   myStat, &
   statUnit = 0_pInt, &                                                                             !< file unit for statistics output
   lastRestartWritten = 0_pInt, &                                                                   !< total increment No. at which last restart information was written
   stagIter, &
   component  
 character(len=6)  :: loadcase_string
 character(len=1024) :: &
   incInfo
 type(tLoadCase), allocatable, dimension(:) :: loadCases                                            !< array of all load cases
 type(tSolutionState), allocatable, dimension(:) :: solres
 PetscInt :: faceSet, currentFaceSet
 PetscInt :: field, dimPlex
 PetscErrorCode :: ierr

 external :: &
   quit

!--------------------------------------------------------------------------------------------------
! init DAMASK (all modules)
 call CPFEM_initAll
 write(6,'(/,a)')   ' <<<+-  DAMASK_FEM init  -+>>>'
 
! reading basic information from load case file and allocate data structure containing load cases
 call DMGetDimension(geomMesh,dimPlex,ierr)! CHKERRQ(ierr)                                            !< dimension of mesh (2D or 3D)
 nActiveFields = 1
 allocate(solres(nActiveFields))

!--------------------------------------------------------------------------------------------------
! reading basic information from load case file and allocate data structure containing load cases
 open(newunit=fileunit,iostat=myStat,file=trim(loadCaseFile),action='read')
 if (myStat /= 0_pInt) call IO_error(100_pInt,el=myStat,ext_msg=trim(loadCaseFile))
 do
   read(fileUnit, '(A)', iostat=myStat) line
   if ( myStat /= 0_pInt) exit
   if (IO_isBlank(line)) cycle                                                                      ! skip empty lines

   chunkPos = IO_stringPos(line)
   do i = 1_pInt, chunkPos(1)                                                                      ! reading compulsory parameters for loadcase
     select case (IO_lc(IO_stringValue(line,chunkPos,i)))
       case('$loadcase')
         N_def = N_def + 1_pInt
     end select
   enddo                                                                                            ! count all identifiers to allocate memory and do sanity check
 enddo

 allocate (loadCases(N_def))         

 do i = 1, size(loadCases)
   allocate(loadCases(i)%fieldBC(nActiveFields))
   field = 1
   loadCases(i)%fieldBC(field)%ID = FIELD_MECH_ID
 enddo

 do i = 1, size(loadCases)
   do field = 1, nActiveFields
     select case (loadCases(i)%fieldBC(field)%ID)
       case(FIELD_MECH_ID)
         loadCases(i)%fieldBC(field)%nComponents = dimPlex                                        !< X, Y (, Z) displacements
         allocate(loadCases(i)%fieldBC(field)%componentBC(loadCases(i)%fieldBC(field)%nComponents))
         do component = 1, loadCases(i)%fieldBC(field)%nComponents
           select case (component)
             case (1)
               loadCases(i)%fieldBC(field)%componentBC(component)%ID = COMPONENT_MECH_X_ID
             case (2)
               loadCases(i)%fieldBC(field)%componentBC(component)%ID = COMPONENT_MECH_Y_ID
             case (3)
               loadCases(i)%fieldBC(field)%componentBC(component)%ID = COMPONENT_MECH_Z_ID
           end select
         enddo  
     end select
     do component = 1, loadCases(i)%fieldBC(field)%nComponents
       allocate(loadCases(i)%fieldBC(field)%componentBC(component)%Value(mesh_Nboundaries), source = 0.0_pReal)
       allocate(loadCases(i)%fieldBC(field)%componentBC(component)%Mask (mesh_Nboundaries), source = .false.)
     enddo
   enddo       
 enddo   

!--------------------------------------------------------------------------------------------------
! reading the load case and assign values to the allocated data structure
 rewind(fileUnit)
 do
   read(fileUnit, '(A)', iostat=myStat) line
   if ( myStat /= 0_pInt) exit
   if (IO_isBlank(line)) cycle                                                                      ! skip empty lines

   chunkPos = IO_stringPos(line)
   do i = 1_pInt, chunkPos(1)
     select case (IO_lc(IO_stringValue(line,chunkPos,i)))
!--------------------------------------------------------------------------------------------------
! loadcase information
       case('$loadcase')
         currentLoadCase = IO_intValue(line,chunkPos,i+1_pInt)
       case('face')
         currentFace = IO_intValue(line,chunkPos,i+1_pInt)
         currentFaceSet = -1_pInt
         do faceSet = 1, mesh_Nboundaries
           if (mesh_boundaries(faceSet) == currentFace) currentFaceSet = faceSet
         enddo
         if (currentFaceSet < 0_pInt) call IO_error(error_ID = errorID, ext_msg = 'invalid BC')  
       case('t','time','delta')                                                                     ! increment time
         loadCases(currentLoadCase)%time = IO_floatValue(line,chunkPos,i+1_pInt)
       case('n','incs','increments','steps')                                                        ! number of increments
         loadCases(currentLoadCase)%incs = IO_intValue(line,chunkPos,i+1_pInt)
       case('logincs','logincrements','logsteps')                                                   ! number of increments (switch to log time scaling)
         loadCases(currentLoadCase)%incs = IO_intValue(line,chunkPos,i+1_pInt)
         loadCases(currentLoadCase)%logscale = 1_pInt
       case('freq','frequency','outputfreq')                                                        ! frequency of result writings
         loadCases(currentLoadCase)%outputfrequency = IO_intValue(line,chunkPos,i+1_pInt)                
       case('r','restart','restartwrite')                                                           ! frequency of writing restart information
         loadCases(currentLoadCase)%restartfrequency = &
               max(0_pInt,IO_intValue(line,chunkPos,i+1_pInt))                
       case('guessreset','dropguessing')
         loadCases(currentLoadCase)%followFormerTrajectory = .false.                                ! do not continue to predict deformation along former trajectory

!--------------------------------------------------------------------------------------------------
! boundary condition information
       case('x')                                                                                    ! X displacement field  
         do field = 1, nActiveFields
           if (loadCases(currentLoadCase)%fieldBC(field)%ID == FIELD_MECH_ID) then
             do component = 1, loadcases(currentLoadCase)%fieldBC(field)%nComponents
               if (loadCases(currentLoadCase)%fieldBC(field)%componentBC(component)%ID == COMPONENT_MECH_X_ID) then
                 loadCases(currentLoadCase)%fieldBC(field)%componentBC(component)%Mask (currentFaceSet) = &
                     .true.
                 loadCases(currentLoadCase)%fieldBC(field)%componentBC(component)%Value(currentFaceSet) = &
                     IO_floatValue(line,chunkPos,i+1_pInt)
               endif
             enddo
           endif
         enddo  
       case('y')                                                                                    ! Y displacement field                                                                            
         do field = 1, nActiveFields
           if (loadCases(currentLoadCase)%fieldBC(field)%ID == FIELD_MECH_ID) then
             do component = 1, loadcases(currentLoadCase)%fieldBC(field)%nComponents
               if (loadCases(currentLoadCase)%fieldBC(field)%componentBC(component)%ID == COMPONENT_MECH_Y_ID) then
                 loadCases(currentLoadCase)%fieldBC(field)%componentBC(component)%Mask (currentFaceSet) = &
                     .true.
                 loadCases(currentLoadCase)%fieldBC(field)%componentBC(component)%Value(currentFaceSet) = &
                     IO_floatValue(line,chunkPos,i+1_pInt)
               endif
             enddo
           endif
         enddo  
       case('z')                                                                                    ! Z displacement field                                                                       
         do field = 1, nActiveFields
           if (loadCases(currentLoadCase)%fieldBC(field)%ID == FIELD_MECH_ID) then
             do component = 1, loadcases(currentLoadCase)%fieldBC(field)%nComponents
               if (loadCases(currentLoadCase)%fieldBC(field)%componentBC(component)%ID == COMPONENT_MECH_Z_ID) then
                 loadCases(currentLoadCase)%fieldBC(field)%componentBC(component)%Mask (currentFaceSet) = &
                     .true.
                 loadCases(currentLoadCase)%fieldBC(field)%componentBC(component)%Value(currentFaceSet) = &
                     IO_floatValue(line,chunkPos,i+1_pInt)
               endif
             enddo
           endif
         enddo  
     end select
 enddo; enddo
 close(fileUnit)
 
!--------------------------------------------------------------------------------------------------
! consistency checks and output of load case
 loadCases(1)%followFormerTrajectory = .false.                                                      ! cannot guess along trajectory for first inc of first currentLoadCase
 errorID = 0_pInt
 checkLoadcases: do currentLoadCase = 1_pInt, size(loadCases)
     write (loadcase_string, '(i6)' ) currentLoadCase
     write(6,'(1x,a,i6)') 'load case: ', currentLoadCase
     if (.not. loadCases(currentLoadCase)%followFormerTrajectory) &
       write(6,'(2x,a)') 'drop guessing along trajectory'
     do field = 1_pInt, nActiveFields
       select case (loadCases(currentLoadCase)%fieldBC(field)%ID)
         case(FIELD_MECH_ID)
           write(6,'(2x,a)') 'Field '//trim(FIELD_MECH_label)
       
       end select
       do faceSet = 1_pInt, mesh_Nboundaries
          do component = 1_pInt, loadCases(currentLoadCase)%fieldBC(field)%nComponents
            if (loadCases(currentLoadCase)%fieldBC(field)%componentBC(component)%Mask(faceSet)) &
              write(6,'(4x,a,i2,a,i2,a,f12.7)') 'Face  ', mesh_boundaries(faceSet), &
                                                ' Component ', component, & 
                                                ' Value ', loadCases(currentLoadCase)%fieldBC(field)% &
                                                             componentBC(component)%Value(faceSet)
          enddo
        enddo       
     enddo
     write(6,'(2x,a,f12.6)') 'time:       ', loadCases(currentLoadCase)%time
     if (loadCases(currentLoadCase)%incs < 1_pInt)             errorID = 835_pInt                     ! non-positive incs count
     write(6,'(2x,a,i5)')    'increments: ', loadCases(currentLoadCase)%incs
     if (loadCases(currentLoadCase)%outputfrequency < 1_pInt)  errorID = 836_pInt                     ! non-positive result frequency
     write(6,'(2x,a,i5)')    'output  frequency:  ', &
                loadCases(currentLoadCase)%outputfrequency
     write(6,'(2x,a,i5,/)')    'restart frequency:  ', &
                loadCases(currentLoadCase)%restartfrequency
     if (errorID > 0_pInt) call IO_error(error_ID = errorID, ext_msg = loadcase_string)               ! exit with error message
 enddo checkLoadcases

!--------------------------------------------------------------------------------------------------
! doing initialization depending on active solvers
 call Utilities_init()
 do field = 1, nActiveFields
   select case (loadCases(1)%fieldBC(field)%ID)
     case(FIELD_MECH_ID)
       call FEM_mech_init(loadCases(1)%fieldBC(field))
   end select
 enddo   


 loadCaseLooping: do currentLoadCase = 1_pInt, size(loadCases)
   time0 = time                                                                                     ! load case start time
   guess = loadCases(currentLoadCase)%followFormerTrajectory                                        ! change of load case? homogeneous guess for the first inc

   incLooping: do inc = 1_pInt, loadCases(currentLoadCase)%incs
     totalIncsCounter = totalIncsCounter + 1_pInt                                                 

!--------------------------------------------------------------------------------------------------
! forwarding time
     timeIncOld = timeinc                                                                           ! last timeinc that brought former inc to an end
     if (loadCases(currentLoadCase)%logscale == 0_pInt) then                                        ! linear scale
       timeinc = loadCases(currentLoadCase)%time/real(loadCases(currentLoadCase)%incs,pReal)
     else
       if (currentLoadCase == 1_pInt) then                                                          ! 1st load case of logarithmic scale
         if (inc == 1_pInt) then                                                                    ! 1st inc of 1st load case of logarithmic scale
           timeinc = loadCases(1)%time*(2.0_pReal**real(    1_pInt-loadCases(1)%incs ,pReal))       ! assume 1st inc is equal to 2nd 
         else                                                                                       ! not-1st inc of 1st load case of logarithmic scale
           timeinc = loadCases(1)%time*(2.0_pReal**real(inc-1_pInt-loadCases(1)%incs ,pReal))
         endif
       else                                                                                         ! not-1st load case of logarithmic scale
         timeinc = time0 * &
              ( (1.0_pReal + loadCases(currentLoadCase)%time/time0 )**(real(          inc,pReal)/&
                                                    real(loadCases(currentLoadCase)%incs ,pReal))&
               -(1.0_pReal + loadCases(currentLoadCase)%time/time0 )**(real( inc-1_pInt  ,pReal)/&
                                                     real(loadCases(currentLoadCase)%incs ,pReal)))
       endif
     endif
     timeinc = timeinc * real(subStepFactor,pReal)**real(-cutBackLevel,pReal)                       ! depending on cut back level, decrease time step

     skipping: if (totalIncsCounter <= restartInc) then                                             ! not yet at restart inc?
       time = time + timeinc                                                                        ! just advance time, skip already performed calculation
       guess = .true.                                                                               ! QUESTION:why forced guessing instead of inheriting loadcase preference
     else skipping
       stepFraction = 0_pInt                                                                        ! fraction scaled by stepFactor**cutLevel

       subStepLooping: do while (stepFraction < subStepFactor**cutBackLevel)
         remainingLoadCaseTime = loadCases(currentLoadCase)%time+time0 - time
         time = time + timeinc                                                                      ! forward target time
         stepFraction = stepFraction + 1_pInt                                                       ! count step
           
!--------------------------------------------------------------------------------------------------
! report begin of new step
           write(6,'(/,a)') ' ###########################################################################'
           write(6,'(1x,a,es12.5'//&
                   ',a,'//IO_intOut(inc)//',a,'//IO_intOut(loadCases(currentLoadCase)%incs)//&
                   ',a,'//IO_intOut(stepFraction)//',a,'//IO_intOut(subStepFactor**cutBackLevel)//&
                   ',a,'//IO_intOut(currentLoadCase)//',a,'//IO_intOut(size(loadCases))//')') &
                   'Time', time, &
                   's: Increment ', inc, '/', loadCases(currentLoadCase)%incs,&
                   '-', stepFraction, '/', subStepFactor**cutBackLevel,&
                   ' of load case ', currentLoadCase,'/',size(loadCases)
         write(incInfo,&
                 '(a,'//IO_intOut(totalIncsCounter)//&
                 ',a,'//IO_intOut(sum(loadCases%incs))//&
                 ',a,'//IO_intOut(stepFraction)//&
                 ',a,'//IO_intOut(subStepFactor**cutBackLevel)//')') &
                 'Increment ',totalIncsCounter,'/',sum(loadCases%incs),&
                 '-',stepFraction, '/', subStepFactor**cutBackLevel
         flush(6)

!--------------------------------------------------------------------------------------------------
! forward fields
         do field = 1, nActiveFields
           select case (loadCases(currentLoadCase)%fieldBC(field)%ID)
             case(FIELD_MECH_ID)
               call FEM_mech_forward (&
                   guess,timeinc,timeIncOld,loadCases(currentLoadCase)%fieldBC(field))

          end select
         enddo       
           
!--------------------------------------------------------------------------------------------------
! solve fields
         stagIter = 0_pInt
         stagIterate = .true.
         do while (stagIterate)
           do field = 1, nActiveFields
             select case (loadCases(currentLoadCase)%fieldBC(field)%ID)
               case(FIELD_MECH_ID)
                 solres(field) = FEM_mech_solution (&
                       incInfo,timeinc,timeIncOld,loadCases(currentLoadCase)%fieldBC(field))

             end select

             if(.not. solres(field)%converged) exit                                                ! no solution found

           enddo
           stagIter = stagIter + 1_pInt
           stagIterate =            stagIter < stagItMax &
                        .and.       all(solres(:)%converged) &
                        .and. .not. all(solres(:)%stagConverged)                                    ! stationary with respect to staggered iteration
         enddo     
           
! check solution 
         cutBack = .False.                                                                   
         if(.not. all(solres(:)%converged .and. solres(:)%stagConverged)) then                      ! no solution found
           if (cutBackLevel < maxCutBack) then                                                   ! do cut back
             if (worldrank == 0) &
               write(6,'(/,a)') ' cut back detected'
             cutBack = .True.
             stepFraction = (stepFraction - 1_pInt) * subStepFactor                                 ! adjust to new denominator
             cutBackLevel = cutBackLevel + 1_pInt
             time    = time - timeinc                                                               ! rewind time
             timeinc = timeinc/2.0_pReal
           else                                                                                     ! default behavior, exit if spectral solver does not converge                                
             call IO_warning(850_pInt)
             call quit(-1_pInt*(lastRestartWritten+1_pInt))                                         ! quit and provide information about last restart inc written (e.g. for regridding)                                                                                       ! continue from non-converged solution and start guessing after accepted (sub)inc
           endif
         else
           guess = .true.                                                                           ! start guessing after first converged (sub)inc
           timeIncOld = timeinc
         endif
         if (.not. cutBack) then
           if (worldrank == 0)  write(statUnit,*) totalIncsCounter, time, cutBackLevel, &
                             solres%converged, solres%iterationsNeeded                              ! write statistics about accepted solution
         endif
       enddo subStepLooping

       cutBackLevel = max(0_pInt, cutBackLevel - 1_pInt)                                            ! try half number of subincs next inc

       if (all(solres(:)%converged)) then
         convergedCounter = convergedCounter + 1_pInt
         write(6,'(/,a,'//IO_intOut(totalIncsCounter)//',a)') &                                     ! report converged inc
                                   ' increment ', totalIncsCounter, ' converged'
       else
         notConvergedCounter = notConvergedCounter + 1_pInt
         write(6,'(/,a,'//IO_intOut(totalIncsCounter)//',a)') &                                     ! report non-converged inc
                                   ' increment ', totalIncsCounter, ' NOT converged'
       endif; flush(6)

       if (mod(inc,loadCases(currentLoadCase)%outputFrequency) == 0_pInt) then                      ! at output frequency
         write(6,'(1/,a)') ' ToDo: ... writing results to file ......................................'
       endif
       if (              loadCases(currentLoadCase)%restartFrequency > 0_pInt &                     ! writing of restart info requested ...
           .and. mod(inc,loadCases(currentLoadCase)%restartFrequency) == 0_pInt) then               ! ... and at frequency of writing restart information
         restartWrite = .true.                                                                      ! set restart parameter for FEsolving
         lastRestartWritten = inc                                                                   ! QUESTION: first call to CPFEM_general will write?
       endif

     endif skipping

    enddo incLooping

 enddo loadCaseLooping
 
 
!--------------------------------------------------------------------------------------------------
! report summary of whole calculation
 write(6,'(/,a)') ' ###########################################################################'
 write(6,'(1x,'//IO_intOut(convergedCounter)//',a,'//IO_intOut(notConvergedCounter + convergedCounter)//',a,f5.1,a)') &
   convergedCounter, ' out of ', &
   notConvergedCounter + convergedCounter, ' (', &
   real(convergedCounter, pReal)/&
   real(notConvergedCounter + convergedCounter,pReal)*100.0_pReal, ' %) increments converged!'
 flush(6)
 call MPI_file_close(fileUnit,ierr)
 close(statUnit)

 if (notConvergedCounter > 0_pInt) call quit(2_pInt)                                                ! error if some are not converged
 call quit(0_pInt)                                                                        ! no complains ;)

end program DAMASK_FEM