From 62ddbf26df4eb2f432ee4b6f4c6edb7aea71de2a Mon Sep 17 00:00:00 2001 From: Christoph Kords Date: Thu, 29 Nov 2012 18:50:25 +0000 Subject: [PATCH] slightly changed the multiplication term in the nonlocal model for the starvation case --- code/config/material.config | 1 - code/constitutive_nonlocal.f90 | 86 ++++++++++++++-------------------- 2 files changed, 36 insertions(+), 51 deletions(-) diff --git a/code/config/material.config b/code/config/material.config index 6061dc773..769a1f3e4 100644 --- a/code/config/material.config +++ b/code/config/material.config @@ -279,7 +279,6 @@ minimumDipoleHeightEdge 2e-9 # minimum distance for stable e minimumDipoleHeightScrew 2e-9 # minimum distance for stable screw dipoles in m (per slip family) lambda0 80 # prefactor for mean free path edgeMultiplication 0.1 # factor to which edges contribute to multiplication -#s0 80 # prefactor for mean dislocation source distance atomicVolume 1.7e-29 # atomic volume in m**3 selfdiffusionPrefactor 1e-4 # prefactor for self-diffusion coefficient in m**2/s selfdiffusionEnergy 2.3e-19 # activation enthalpy for seld-diffusion in J diff --git a/code/constitutive_nonlocal.f90 b/code/constitutive_nonlocal.f90 index e2d70abd2..e98a348a9 100644 --- a/code/constitutive_nonlocal.f90 +++ b/code/constitutive_nonlocal.f90 @@ -134,8 +134,7 @@ constitutive_nonlocal_CFLfactor, & ! safety fa constitutive_nonlocal_fEdgeMultiplication, & ! factor that determines how much edge dislocations contribute to multiplication (0...1) constitutive_nonlocal_rhoSglRandom, & constitutive_nonlocal_rhoSglRandomBinning, & -constitutive_nonlocal_linetensionEffect, & -constitutive_nonlocal_s0 +constitutive_nonlocal_linetensionEffect real(pReal), dimension(:,:), allocatable, private :: & constitutive_nonlocal_rhoSglEdgePos0, & ! initial edge_pos dislocation density per slip system for each family and instance @@ -163,7 +162,8 @@ constitutive_nonlocal_interactionMatrixSlipSlip ! interacti real(pReal), dimension(:,:,:,:), allocatable, private :: & constitutive_nonlocal_lattice2slip, & ! orthogonal transformation matrix from lattice coordinate system to slip coordinate system (passive rotation !!!) constitutive_nonlocal_accumulatedShear, & ! accumulated shear per slip system up to the start of the FE increment -constitutive_nonlocal_rhoDotEdgeJogs +constitutive_nonlocal_rhoDotEdgeJogs, & +constitutive_nonlocal_sourceProbability real(pReal), dimension(:,:,:,:,:), allocatable, private :: & constitutive_nonlocal_Cslip_3333, & ! elasticity matrix for each instance @@ -180,10 +180,6 @@ logical, dimension(:), allocatable, private :: & constitutive_nonlocal_shortRangeStressCorrection, & ! flag indicating the use of the short range stress correction by a excess density gradient term constitutive_nonlocal_deadZoneScaling -logical, dimension(:,:,:,:), allocatable, private :: & -constitutive_nonlocal_manyActiveSources, & -constitutive_nonlocal_singleActiveSource - public :: & constitutive_nonlocal_init, & constitutive_nonlocal_stateInit, & @@ -354,7 +350,6 @@ allocate(constitutive_nonlocal_deadZoneScaling(maxNinstance)) allocate(constitutive_nonlocal_CFLfactor(maxNinstance)) allocate(constitutive_nonlocal_fEdgeMultiplication(maxNinstance)) allocate(constitutive_nonlocal_linetensionEffect(maxNinstance)) -allocate(constitutive_nonlocal_s0(maxNinstance)) constitutive_nonlocal_CoverA = 0.0_pReal constitutive_nonlocal_C11 = 0.0_pReal constitutive_nonlocal_C12 = 0.0_pReal @@ -389,7 +384,6 @@ constitutive_nonlocal_grainboundaryTransmissivity = -1.0_pReal constitutive_nonlocal_CFLfactor = 2.0_pReal constitutive_nonlocal_fEdgeMultiplication = 0.0_pReal constitutive_nonlocal_linetensionEffect = 0.0_pReal -constitutive_nonlocal_s0 = 0.0_pReal constitutive_nonlocal_shortRangeStressCorrection = .false. constitutive_nonlocal_deadZoneScaling = .false. @@ -553,8 +547,6 @@ do constitutive_nonlocal_shortRangeStressCorrection(i) = IO_floatValue(line,positions,2_pInt) > 0.0_pReal case('deadzonescaling','deadzone','deadscaling') constitutive_nonlocal_deadZoneScaling(i) = IO_floatValue(line,positions,2_pInt) > 0.0_pReal - case('s0') - constitutive_nonlocal_s0(i) = IO_floatValue(line,positions,2_pInt) case default call IO_error(210_pInt,ext_msg=tag//' ('//constitutive_nonlocal_label//')') end select @@ -664,8 +656,6 @@ enddo if (constitutive_nonlocal_fEdgeMultiplication(i) < 0.0_pReal .or. constitutive_nonlocal_fEdgeMultiplication(i) > 1.0_pReal) & call IO_error(211_pInt,ext_msg='edgemultiplicationfactor ('& //constitutive_nonlocal_label//')') - if (constitutive_nonlocal_s0(i) < 0.0_pReal) call IO_error(211_pInt,ext_msg='s0 (' & - //constitutive_nonlocal_label//')') !*** determine total number of active slip systems @@ -705,11 +695,8 @@ constitutive_nonlocal_lattice2slip = 0.0_pReal allocate(constitutive_nonlocal_accumulatedShear(maxTotalNslip, homogenization_maxNgrains, mesh_maxNips, mesh_NcpElems)) constitutive_nonlocal_accumulatedShear = 0.0_pReal -allocate(constitutive_nonlocal_manyActiveSources(maxTotalNslip, homogenization_maxNgrains, mesh_maxNips, mesh_NcpElems)) -constitutive_nonlocal_manyActiveSources = .true. - -allocate(constitutive_nonlocal_singleActiveSource(maxTotalNslip, homogenization_maxNgrains, mesh_maxNips, mesh_NcpElems)) -constitutive_nonlocal_singleActiveSource = .false. +allocate(constitutive_nonlocal_sourceProbability(maxTotalNslip, homogenization_maxNgrains, mesh_maxNips, mesh_NcpElems)) +constitutive_nonlocal_sourceProbability = 2.0_pReal allocate(constitutive_nonlocal_rhoDotFlux(maxTotalNslip, 8, homogenization_maxNgrains, mesh_maxNips, mesh_NcpElems)) allocate(constitutive_nonlocal_rhoDotMultiplication(maxTotalNslip, 2, homogenization_maxNgrains, mesh_maxNips, mesh_NcpElems)) @@ -2100,6 +2087,7 @@ real(pReal), dimension(constitutive_nonlocal_totalNslip(phase_plasticityInstance rhoDotThermalAnnihilation ! density evolution by thermal annihilation real(pReal), dimension(constitutive_nonlocal_totalNslip(phase_plasticityInstance(material_phase(g,ip,el))),8) :: & rhoSgl, & ! current single dislocation densities (positive/negative screw and edge without dipoles) + rhoSglOriginal, & rhoSgl0, & ! single dislocation densities at start of cryst inc (positive/negative screw and edge without dipoles) rhoSglMe, & ! single dislocation densities of central ip (positive/negative screw and edge without dipoles) neighboring_rhoSgl ! current single dislocation densities of neighboring ip (positive/negative screw and edge without dipoles) @@ -2111,11 +2099,11 @@ real(pReal), dimension(constitutive_nonlocal_totalNslip(phase_plasticityInstance gdot ! shear rates real(pReal), dimension(constitutive_nonlocal_totalNslip(phase_plasticityInstance(material_phase(g,ip,el)))) :: & rhoForest, & ! forest dislocation density - rhoSource, & ! density of dislocation nucleation sources tauThreshold, & ! threshold shear stress tau, & ! current resolved shear stress tauBack, & ! current back stress from pileups on same slip system - vClimb ! climb velocity of edge dipoles + vClimb, & ! climb velocity of edge dipoles + nSources real(pReal), dimension(constitutive_nonlocal_totalNslip(phase_plasticityInstance(material_phase(g,ip,el))),2) :: & rhoDip, & ! current dipole dislocation densities (screw and edge dipoles) dLower, & ! minimum stable dipole distance for edges and screws @@ -2135,10 +2123,10 @@ real(pReal) area, & ! area transmissivity, & ! overall transmissivity of dislocation flux to neighboring material point lineLength, & ! dislocation line length leaving the current interface D, & ! self diffusion - rnd + rnd, & + meshlength logical considerEnteringFlux, & - considerLeavingFlux, & - wasActive + considerLeavingFlux #ifndef _OPENMP if (iand(debug_level(debug_constitutive),debug_levelBasic) /= 0_pInt & @@ -2172,6 +2160,7 @@ tauThreshold = state(g,ip,el)%p(11_pInt*ns+1_pInt:12_pInt*ns) tauBack = state(g,ip,el)%p(12_pInt*ns+1:13_pInt*ns) forall (t = 1_pInt:4_pInt) & v(1_pInt:ns,t) = state(g,ip,el)%p((12_pInt+t)*ns+1_pInt:(13_pInt+t)*ns) +rhoSglOriginal = rhoSgl where (abs(rhoSgl) * mesh_ipVolume(ip,el) ** 0.667_pReal < constitutive_nonlocal_significantN(myInstance) & .or. abs(rhoSgl) < constitutive_nonlocal_significantRho(myInstance)) & rhoSgl = 0.0_pReal @@ -2232,41 +2221,38 @@ dUpper = max(dUpper,dLower) !*** calculate dislocation multiplication rhoDotMultiplication = 0.0_pReal -if (constitutive_nonlocal_s0(myInstance) > 0.0_pReal) then - rhoSource(1:ns) = (sum(rhoSgl(1:ns,1:2),2) * constitutive_nonlocal_fEdgeMultiplication(myInstance) + sum(rhoSgl(1:ns,3:4),2)) & - * sqrt(rhoForest(1:ns)) / constitutive_nonlocal_s0(myInstance) - do s = 1_pInt,ns - wasActive = constitutive_nonlocal_manyActiveSources(s,g,ip,el) - constitutive_nonlocal_manyActiveSources(s,g,ip,el) = rhoSource(s) * mesh_ipVolume(ip,el) > 1.0_pReal - if (rhoSource(s) * mesh_ipVolume(ip,el) > 1.0_pReal) then - rhoDotMultiplication(s,1:4) = (sum(abs(gdot(s,1:2))) * constitutive_nonlocal_fEdgeMultiplication(myInstance) & - + sum(abs(gdot(s,3:4)))) / constitutive_nonlocal_burgers(s,myInstance) & - * sqrt(rhoForest(s)) / constitutive_nonlocal_lambda0(s,myInstance) - else - if (wasActive) then - call random_number(rnd) - constitutive_nonlocal_singleActiveSource(s,g,ip,el) = rhoSource(s) * mesh_ipVolume(ip,el) > rnd - !$OMP FLUSH(constitutive_nonlocal_singleActiveSource) - endif - if (constitutive_nonlocal_singleActiveSource(s,g,ip,el)) then - rhoDotMultiplication(s,1:4) = abs(v(s,1:4)) / mesh_ipVolume(ip,el) * constitutive_nonlocal_s0(myInstance) & - / constitutive_nonlocal_lambda0(s,myInstance) - endif +meshlength = mesh_ipVolume(ip,el)**0.333_pReal +where(sum(rhoSgl(1:ns,1:4),2) > 0.0_pReal) + nSources = (sum(rhoSgl(1:ns,1:2),2) * constitutive_nonlocal_fEdgeMultiplication(myInstance) + sum(rhoSgl(1:ns,3:4),2)) & + / sum(rhoSgl(1:ns,1:4),2) * meshlength / constitutive_nonlocal_lambda0(1:ns,myInstance) * sqrt(rhoForest(1:ns)) +elsewhere + nSources = meshlength / constitutive_nonlocal_lambda0(1:ns,myInstance) * sqrt(rhoForest(1:ns)) +endwhere +do s = 1_pInt,ns + if (nSources(s) < 1.0_pReal) then + if (constitutive_nonlocal_sourceProbability(s,g,ip,el) > 1.0_pReal) then + call random_number(rnd) + constitutive_nonlocal_sourceProbability(s,g,ip,el) = rnd + !$OMP FLUSH(constitutive_nonlocal_sourceProbability) endif - enddo + if (constitutive_nonlocal_sourceProbability(s,g,ip,el) > 1.0_pReal - nSources(s)) then + rhoDotMultiplication(s,1:4) = sum(rhoSglOriginal(1:ns,1:4),2) * abs(v(s,1:4)) / meshlength + endif + else + constitutive_nonlocal_sourceProbability(s,g,ip,el) = 2.0_pReal + rhoDotMultiplication(s,1:4) = & + (sum(abs(gdot(s,1:2))) * constitutive_nonlocal_fEdgeMultiplication(myInstance) + sum(abs(gdot(s,3:4)))) & + / constitutive_nonlocal_burgers(s,myInstance) * sqrt(rhoForest(s)) / constitutive_nonlocal_lambda0(s,myInstance) + endif +enddo #ifndef _OPENMP if (iand(debug_level(debug_constitutive),debug_levelExtensive) /= 0_pInt & .and. ((debug_e == el .and. debug_i == ip .and. debug_g == g)& .or. .not. iand(debug_level(debug_constitutive),debug_levelSelective) /= 0_pInt )) then - write(6,'(a,/,4(12x,12(f12.5,1x),/))') '<< CONST >> sources', rhoSource * mesh_ipVolume(ip,el) + write(6,'(a,/,4(12x,12(f12.5,1x),/))') '<< CONST >> sources', nSources write(6,*) endif #endif -else - rhoDotMultiplication(1:ns,1:4) = spread( & - (sum(abs(gdot(1:ns,1:2)),2) * constitutive_nonlocal_fEdgeMultiplication(myInstance) + sum(abs(gdot(1:ns,3:4)),2)) & - * sqrt(rhoForest) / constitutive_nonlocal_lambda0(1:ns,myInstance) / constitutive_nonlocal_burgers(1:ns,myInstance), 2, 4) -endif