!-------------------------------------------------------------------------------------------------- !> @author Philip Eisenlohr, Michigan State University !> @author Zhuowen Zhao, Michigan State University !> @author Martin Diehl, Max-Planck-Institut für Eisenforschung GmbH !> @brief Phenomenological crystal plasticity using a power law formulation for the shear rates !! and a Voce-type kinematic hardening rule !-------------------------------------------------------------------------------------------------- submodule(constitutive) plastic_kinehardening type :: tParameters real(pReal) :: & gdot0 = 1.0_pReal, & !< reference shear strain rate for slip n = 1.0_pReal !< stress exponent for slip real(pReal), allocatable, dimension(:) :: & theta0, & !< initial hardening rate of forward stress for each slip theta1, & !< asymptotic hardening rate of forward stress for each slip theta0_b, & !< initial hardening rate of back stress for each slip theta1_b, & !< asymptotic hardening rate of back stress for each slip tau1, & tau1_b real(pReal), allocatable, dimension(:,:) :: & interaction_slipslip !< slip resistance from slip activity real(pReal), allocatable, dimension(:,:,:) :: & P, & nonSchmid_pos, & nonSchmid_neg integer :: & sum_N_sl, & !< total number of active slip system of_debug = 0 logical :: & nonSchmidActive = .false. character(len=pStringLen), allocatable, dimension(:) :: & output end type tParameters type :: tKinehardeningState real(pReal), pointer, dimension(:,:) :: & !< vectors along NipcMyInstance crss, & !< critical resolved stress crss_back, & !< critical resolved back stress sense, & !< sense of acting shear stress (-1 or +1) chi0, & !< backstress at last switch of stress sense gamma0, & !< accumulated shear at last switch of stress sense accshear !< accumulated (absolute) shear end type tKinehardeningState !-------------------------------------------------------------------------------------------------- ! containers for parameters and state type(tParameters), allocatable, dimension(:) :: param type(tKinehardeningState), allocatable, dimension(:) :: & dotState, & deltaState, & state contains !-------------------------------------------------------------------------------------------------- !> @brief Perform module initialization. !> @details reads in material parameters, allocates arrays, and does sanity checks !-------------------------------------------------------------------------------------------------- module subroutine plastic_kinehardening_init integer :: & Ninstance, & p, o, & NipcMyPhase, & sizeState, sizeDeltaState, sizeDotState, & startIndex, endIndex integer, dimension(:), allocatable :: & N_sl real(pReal), dimension(:), allocatable :: & xi_0, & !< initial resistance against plastic flow a !< non-Schmid coefficients character(len=pStringLen) :: & extmsg = '' write(6,'(/,a)') ' <<<+- plastic_'//PLASTICITY_KINEHARDENING_LABEL//' init -+>>>'; flush(6) Ninstance = count(phase_plasticity == PLASTICITY_KINEHARDENING_ID) if (iand(debug_level(debug_constitutive),debug_levelBasic) /= 0) & write(6,'(a16,1x,i5,/)') '# instances:',Ninstance allocate(param(Ninstance)) allocate(state(Ninstance)) allocate(dotState(Ninstance)) allocate(deltaState(Ninstance)) do p = 1, size(phase_plasticityInstance) if (phase_plasticity(p) /= PLASTICITY_KINEHARDENING_ID) cycle associate(prm => param(phase_plasticityInstance(p)), & dot => dotState(phase_plasticityInstance(p)), & dlt => deltaState(phase_plasticityInstance(p)), & stt => state(phase_plasticityInstance(p)),& config => config_phase(p)) prm%output = config%getStrings('(output)',defaultVal=emptyStringArray) #ifdef DEBUG if (p==material_phaseAt(debug_g,debug_e)) then prm%of_debug = material_phasememberAt(debug_g,debug_i,debug_e) endif #endif !-------------------------------------------------------------------------------------------------- ! slip related parameters N_sl = config%getInts('nslip',defaultVal=emptyIntArray) prm%sum_N_sl = sum(abs(N_sl)) slipActive: if (prm%sum_N_sl > 0) then prm%P = lattice_SchmidMatrix_slip(N_sl,config%getString('lattice_structure'),& config%getFloat('c/a',defaultVal=0.0_pReal)) if(trim(config%getString('lattice_structure')) == 'bcc') then a = config%getFloats('nonschmid_coefficients',defaultVal = emptyRealArray) if(size(a) > 0) prm%nonSchmidActive = .true. prm%nonSchmid_pos = lattice_nonSchmidMatrix(N_sl,a,+1) prm%nonSchmid_neg = lattice_nonSchmidMatrix(N_sl,a,-1) else prm%nonSchmid_pos = prm%P prm%nonSchmid_neg = prm%P endif prm%interaction_SlipSlip = lattice_interaction_SlipBySlip(N_sl, & config%getFloats('interaction_slipslip'), & config%getString('lattice_structure')) xi_0 = config%getFloats('crss0', requiredSize=size(N_sl)) prm%tau1 = config%getFloats('tau1', requiredSize=size(N_sl)) prm%tau1_b = config%getFloats('tau1_b', requiredSize=size(N_sl)) prm%theta0 = config%getFloats('theta0', requiredSize=size(N_sl)) prm%theta1 = config%getFloats('theta1', requiredSize=size(N_sl)) prm%theta0_b = config%getFloats('theta0_b', requiredSize=size(N_sl)) prm%theta1_b = config%getFloats('theta1_b', requiredSize=size(N_sl)) prm%gdot0 = config%getFloat('gdot0') prm%n = config%getFloat('n_slip') ! expand: family => system xi_0 = math_expand(xi_0, N_sl) prm%tau1 = math_expand(prm%tau1, N_sl) prm%tau1_b = math_expand(prm%tau1_b, N_sl) prm%theta0 = math_expand(prm%theta0, N_sl) prm%theta1 = math_expand(prm%theta1, N_sl) prm%theta0_b = math_expand(prm%theta0_b,N_sl) prm%theta1_b = math_expand(prm%theta1_b,N_sl) !-------------------------------------------------------------------------------------------------- ! sanity checks if ( prm%gdot0 <= 0.0_pReal) extmsg = trim(extmsg)//' gdot0' if ( prm%n <= 0.0_pReal) extmsg = trim(extmsg)//' n_slip' if (any(xi_0 <= 0.0_pReal)) extmsg = trim(extmsg)//' crss0' if (any(prm%tau1 <= 0.0_pReal)) extmsg = trim(extmsg)//' tau1' if (any(prm%tau1_b <= 0.0_pReal)) extmsg = trim(extmsg)//' tau1_b' !ToDo: Any sensible checks for theta? else slipActive xi_0 = emptyRealArray allocate(prm%tau1,prm%tau1_b,prm%theta0,prm%theta1,prm%theta0_b,prm%theta1_b,source=emptyRealArray) allocate(prm%interaction_SlipSlip(0,0)) endif slipActive !-------------------------------------------------------------------------------------------------- ! allocate state arrays NipcMyPhase = count(material_phaseAt == p) * discretization_nIP sizeDotState = size(['crss ','crss_back', 'accshear ']) * prm%sum_N_sl sizeDeltaState = size(['sense ', 'chi0 ', 'gamma0' ]) * prm%sum_N_sl sizeState = sizeDotState + sizeDeltaState call material_allocatePlasticState(p,NipcMyPhase,sizeState,sizeDotState,sizeDeltaState) !-------------------------------------------------------------------------------------------------- ! state aliases and initialization startIndex = 1 endIndex = prm%sum_N_sl stt%crss => plasticState(p)%state (startIndex:endIndex,:) stt%crss = spread(xi_0, 2, NipcMyPhase) dot%crss => plasticState(p)%dotState(startIndex:endIndex,:) plasticState(p)%atol(startIndex:endIndex) = config%getFloat('atol_xi',defaultVal=1.0_pReal) if(any(plasticState(p)%atol(startIndex:endIndex) < 0.0_pReal)) extmsg = trim(extmsg)//' atol_xi' startIndex = endIndex + 1 endIndex = endIndex + prm%sum_N_sl stt%crss_back => plasticState(p)%state (startIndex:endIndex,:) dot%crss_back => plasticState(p)%dotState(startIndex:endIndex,:) plasticState(p)%atol(startIndex:endIndex) = config%getFloat('atol_xi',defaultVal=1.0_pReal) startIndex = endIndex + 1 endIndex = endIndex + prm%sum_N_sl stt%accshear => plasticState(p)%state (startIndex:endIndex,:) dot%accshear => plasticState(p)%dotState(startIndex:endIndex,:) plasticState(p)%atol(startIndex:endIndex) = config%getFloat('atol_gamma',defaultVal=1.0e-6_pReal) if(any(plasticState(p)%atol(startIndex:endIndex) < 0.0_pReal)) extmsg = trim(extmsg)//' atol_gamma' ! global alias plasticState(p)%slipRate => plasticState(p)%dotState(startIndex:endIndex,:) o = plasticState(p)%offsetDeltaState startIndex = endIndex + 1 endIndex = endIndex + prm%sum_N_sl stt%sense => plasticState(p)%state (startIndex :endIndex ,:) dlt%sense => plasticState(p)%deltaState(startIndex-o:endIndex-o,:) startIndex = endIndex + 1 endIndex = endIndex + prm%sum_N_sl stt%chi0 => plasticState(p)%state (startIndex :endIndex ,:) dlt%chi0 => plasticState(p)%deltaState(startIndex-o:endIndex-o,:) startIndex = endIndex + 1 endIndex = endIndex + prm%sum_N_sl stt%gamma0 => plasticState(p)%state (startIndex :endIndex ,:) dlt%gamma0 => plasticState(p)%deltaState(startIndex-o:endIndex-o,:) plasticState(p)%state0 = plasticState(p)%state ! ToDo: this could be done centrally end associate !-------------------------------------------------------------------------------------------------- ! exit if any parameter is out of range if (extmsg /= '') call IO_error(211,ext_msg=trim(extmsg)//'('//PLASTICITY_KINEHARDENING_LABEL//')') enddo end subroutine plastic_kinehardening_init !-------------------------------------------------------------------------------------------------- !> @brief Calculate plastic velocity gradient and its tangent. !-------------------------------------------------------------------------------------------------- pure module subroutine plastic_kinehardening_LpAndItsTangent(Lp,dLp_dMp,Mp,instance,of) real(pReal), dimension(3,3), intent(out) :: & Lp !< plastic velocity gradient real(pReal), dimension(3,3,3,3), intent(out) :: & dLp_dMp !< derivative of Lp with respect to the Mandel stress real(pReal), dimension(3,3), intent(in) :: & Mp !< Mandel stress integer, intent(in) :: & instance, & of integer :: & i,k,l,m,n real(pReal), dimension(param(instance)%sum_N_sl) :: & gdot_pos,gdot_neg, & dgdot_dtau_pos,dgdot_dtau_neg Lp = 0.0_pReal dLp_dMp = 0.0_pReal associate(prm => param(instance)) call kinetics(Mp,instance,of,gdot_pos,gdot_neg,dgdot_dtau_pos,dgdot_dtau_neg) do i = 1, prm%sum_N_sl Lp = Lp + (gdot_pos(i)+gdot_neg(i))*prm%P(1:3,1:3,i) forall (k=1:3,l=1:3,m=1:3,n=1:3) & dLp_dMp(k,l,m,n) = dLp_dMp(k,l,m,n) & + dgdot_dtau_pos(i) * prm%P(k,l,i) * prm%nonSchmid_pos(m,n,i) & + dgdot_dtau_neg(i) * prm%P(k,l,i) * prm%nonSchmid_neg(m,n,i) enddo end associate end subroutine plastic_kinehardening_LpAndItsTangent !-------------------------------------------------------------------------------------------------- !> @brief Calculate the rate of change of microstructure. !-------------------------------------------------------------------------------------------------- module subroutine plastic_kinehardening_dotState(Mp,instance,of) real(pReal), dimension(3,3), intent(in) :: & Mp !< Mandel stress integer, intent(in) :: & instance, & of real(pReal) :: & sumGamma real(pReal), dimension(param(instance)%sum_N_sl) :: & gdot_pos,gdot_neg associate(prm => param(instance), stt => state(instance), dot => dotState(instance)) call kinetics(Mp,instance,of,gdot_pos,gdot_neg) dot%accshear(:,of) = abs(gdot_pos+gdot_neg) sumGamma = sum(stt%accshear(:,of)) dot%crss(:,of) = matmul(prm%interaction_SlipSlip,dot%accshear(:,of)) & * ( prm%theta1 & + (prm%theta0 - prm%theta1 + prm%theta0*prm%theta1*sumGamma/prm%tau1) & * exp(-sumGamma*prm%theta0/prm%tau1) & ) dot%crss_back(:,of) = stt%sense(:,of)*dot%accshear(:,of) * & ( prm%theta1_b + & (prm%theta0_b - prm%theta1_b & + prm%theta0_b*prm%theta1_b/(prm%tau1_b+stt%chi0(:,of))*(stt%accshear(:,of)-stt%gamma0(:,of))& ) *exp(-(stt%accshear(:,of)-stt%gamma0(:,of)) *prm%theta0_b/(prm%tau1_b+stt%chi0(:,of))) & ) end associate end subroutine plastic_kinehardening_dotState !-------------------------------------------------------------------------------------------------- !> @brief Calculate (instantaneous) incremental change of microstructure. !-------------------------------------------------------------------------------------------------- module subroutine plastic_kinehardening_deltaState(Mp,instance,of) real(pReal), dimension(3,3), intent(in) :: & Mp !< Mandel stress integer, intent(in) :: & instance, & of real(pReal), dimension(param(instance)%sum_N_sl) :: & gdot_pos,gdot_neg, & sense associate(prm => param(instance), stt => state(instance), dlt => deltaState(instance)) call kinetics(Mp,instance,of,gdot_pos,gdot_neg) sense = merge(state(instance)%sense(:,of), & ! keep existing... sign(1.0_pReal,gdot_pos+gdot_neg), & ! ...or have a defined dEq0(gdot_pos+gdot_neg,1e-10_pReal)) ! current sense of shear direction #ifdef DEBUG if (iand(debug_level(debug_constitutive), debug_levelExtensive) /= 0 & .and. (of == prm%of_debug & .or. .not. iand(debug_level(debug_constitutive),debug_levelSelective) /= 0)) then write(6,'(a)') '======= kinehardening delta state =======' write(6,*) sense,state(instance)%sense(:,of) endif #endif !-------------------------------------------------------------------------------------------------- ! switch in sense of shear? where(dNeq(sense,stt%sense(:,of),0.1_pReal)) dlt%sense (:,of) = sense - stt%sense(:,of) ! switch sense dlt%chi0 (:,of) = abs(stt%crss_back(:,of)) - stt%chi0(:,of) ! remember current backstress magnitude dlt%gamma0(:,of) = stt%accshear(:,of) - stt%gamma0(:,of) ! remember current accumulated shear else where dlt%sense (:,of) = 0.0_pReal dlt%chi0 (:,of) = 0.0_pReal dlt%gamma0(:,of) = 0.0_pReal end where end associate end subroutine plastic_kinehardening_deltaState !-------------------------------------------------------------------------------------------------- !> @brief Write results to HDF5 output file. !-------------------------------------------------------------------------------------------------- module subroutine plastic_kinehardening_results(instance,group) integer, intent(in) :: instance character(len=*), intent(in) :: group integer :: o associate(prm => param(instance), stt => state(instance)) outputsLoop: do o = 1,size(prm%output) select case(trim(prm%output(o))) case('resistance') if(prm%sum_N_sl>0) call results_writeDataset(group,stt%crss,'xi_sl', & 'resistance against plastic slip','Pa') case('backstress') ! ToDo: should be 'tau_back' if(prm%sum_N_sl>0) call results_writeDataset(group,stt%crss_back,'tau_back', & 'back stress against plastic slip','Pa') case ('sense') if(prm%sum_N_sl>0) call results_writeDataset(group,stt%sense,'sense_of_shear', & 'tbd','1') case ('chi0') if(prm%sum_N_sl>0) call results_writeDataset(group,stt%chi0,'chi0', & 'tbd','Pa') case ('gamma0') if(prm%sum_N_sl>0) call results_writeDataset(group,stt%gamma0,'gamma0', & 'tbd','1') case ('accumulatedshear') if(prm%sum_N_sl>0) call results_writeDataset(group,stt%accshear,'gamma_sl', & 'plastic shear','1') end select enddo outputsLoop end associate end subroutine plastic_kinehardening_results !-------------------------------------------------------------------------------------------------- !> @brief Calculate shear rates on slip systems and their derivatives with respect to resolved ! stress. !> @details: Derivatives are calculated only optionally. ! NOTE: Against the common convention, the result (i.e. intent(out)) variables are the last to ! have the optional arguments at the end. !-------------------------------------------------------------------------------------------------- pure subroutine kinetics(Mp,instance,of, & gdot_pos,gdot_neg,dgdot_dtau_pos,dgdot_dtau_neg) real(pReal), dimension(3,3), intent(in) :: & Mp !< Mandel stress integer, intent(in) :: & instance, & of real(pReal), intent(out), dimension(param(instance)%sum_N_sl) :: & gdot_pos, & gdot_neg real(pReal), intent(out), optional, dimension(param(instance)%sum_N_sl) :: & dgdot_dtau_pos, & dgdot_dtau_neg real(pReal), dimension(param(instance)%sum_N_sl) :: & tau_pos, & tau_neg integer :: i associate(prm => param(instance), stt => state(instance)) do i = 1, prm%sum_N_sl tau_pos(i) = math_tensordot(Mp,prm%nonSchmid_pos(1:3,1:3,i)) - stt%crss_back(i,of) tau_neg(i) = merge(math_tensordot(Mp,prm%nonSchmid_neg(1:3,1:3,i)) - stt%crss_back(i,of), & 0.0_pReal, prm%nonSchmidActive) enddo where(dNeq0(tau_pos)) gdot_pos = prm%gdot0 * merge(0.5_pReal,1.0_pReal, prm%nonSchmidActive) & ! 1/2 if non-Schmid active * sign(abs(tau_pos/stt%crss(:,of))**prm%n, tau_pos) else where gdot_pos = 0.0_pReal end where where(dNeq0(tau_neg)) gdot_neg = prm%gdot0 * 0.5_pReal & ! only used if non-Schmid active, always 1/2 * sign(abs(tau_neg/stt%crss(:,of))**prm%n, tau_neg) else where gdot_neg = 0.0_pReal end where if (present(dgdot_dtau_pos)) then where(dNeq0(gdot_pos)) dgdot_dtau_pos = gdot_pos*prm%n/tau_pos else where dgdot_dtau_pos = 0.0_pReal end where endif if (present(dgdot_dtau_neg)) then where(dNeq0(gdot_neg)) dgdot_dtau_neg = gdot_neg*prm%n/tau_neg else where dgdot_dtau_neg = 0.0_pReal end where endif end associate end subroutine kinetics end submodule plastic_kinehardening