// Calculate J and K at crack tips
CustomTask *PropagateTask::StepCalculation(void)
{
// if not needed, just exit
if(!doPropCalcs) return nextTask;
// particle extrapolation if needed
if(doEnergyBalanceCalcs)
{ totalPlastic = 0.;
totalPotential = 0.;
for(int p=0;p<nmpmsNR;p++)
{ MPMBase *mpnt = mpm[p];
// track total energies in J = N-m
// mp is g, stored energy is N/m^2 cm^3/g, vel is mm/sec
// workEnergy in J = 1.0e-6*mp*mpm[p]->GetWorkEnergy()
// plastic 1.0e-6*mp*mpm[p]->GetPlastEnergy()
// external work 1.e-9*mpm[p]->GetExtWork()
// kinetic energy 0.5e-9*mp*(vel.x*vel.x+vel.y*vel.y)
// plastic energy per unit thickness (units of N) (only needed energy balance crack growth)
double mp = mpnt->mp;
totalPlastic += 1.0e-3*mp*mpnt->GetPlastEnergy()/mpnt->thickness();
//totalPotential += 1.0e-3*(mp*mpnt->GetStrainEnergy()
// + 0.5e-3*mp*(mpnt->vel.x*mpnt->vel.x+mpnt->vel.y*mpnt->vel.y)
// - 1.e-3*mpnt->GetExtWork())/mpnt->thickness();
throw "external work is no longer available";
}
}
CrackHeader *nextCrack;
CrackSegment *crkTip;
double cSize;
int i,inMat;
Vector tipDir,growTo,grow;
int tipElem;
char isAlt[10];
// loop over cracks
nextCrack=firstCrack;
while(nextCrack!=NULL)
{ // each crack tip
for(i=START_OF_CRACK;i<=END_OF_CRACK;i++)
{ // find crack tip and direction
nextCrack->CrackTipAndDirection(i,&crkTip,tipDir);
// crack propagation
inMat=crkTip->tipMatnum;
if(inMat>0)
{ // crack tip terms last two times propagated
crkTip->potential[2]=crkTip->potential[1];
crkTip->potential[1]=crkTip->potential[0];
crkTip->potential[0]=totalPotential;
crkTip->plastic[2]=crkTip->plastic[1];
crkTip->plastic[1]=crkTip->plastic[0];
crkTip->plastic[0]=totalPlastic;
crkTip->clength[2]=crkTip->clength[1];
crkTip->clength[1]=crkTip->clength[0];
crkTip->clength[0]=nextCrack->Length();
// see if it grows
int shouldGo=theMaterials[inMat-1]->ShouldPropagate(crkTip,tipDir,nextCrack,fmobj->np,0);
isAlt[0] = 0;
if(shouldGo==GROWNOW)
{ nextCrack->SetAllowAlternate(i,FALSE);
}
else if(nextCrack->GetAllowAlternate(i))
{ shouldGo=theMaterials[inMat-1]->ShouldPropagate(crkTip,tipDir,nextCrack,fmobj->np,1);
if(shouldGo==GROWNOW) strcpy(isAlt," (alt)");
}
if(shouldGo==GROWNOW)
{ theResult=GROWNOW;
tipElem=crkTip->planeInElem-1;
if(fabs(tipDir.x)>fabs(tipDir.y))
cSize=theElements[tipElem]->xmax-theElements[tipElem]->xmin;
else
cSize=theElements[tipElem]->ymax-theElements[tipElem]->ymin;
grow.x=cellsPerPropagationStep*cSize*tipDir.x;
grow.y=cellsPerPropagationStep*cSize*tipDir.y;
// adjust if crossing another crack
double p = nextCrack->AdjustGrowForCrossing(&grow,crkTip);
// crack number and tip
archiver->IncrementPropagationCounter();
cout << "# propagation" << isAlt << " crack-tip " << nextCrack->GetNumber() << "-" << i;
// summarize
cout << " at t=" << 1000*mtime << " with J=Jtip+Jzone : " << 1000.*crkTip->Jint.z <<
" = " << 1000.*crkTip->Jint.x << " + " << 1000.*(crkTip->Jint.z-crkTip->Jint.x) << endl;
// if jump is .7 or more cells, make more than 1 segment
int iseg,numSegs = 1;
if(p*cellsPerPropagationStep>.7) numSegs= 2*(p*cellsPerPropagationStep+.25);
CrackSegment *newCrkTip;
for(iseg=1;iseg<=numSegs;iseg++)
{ growTo.x=crkTip->x+(double)iseg*grow.x/(double)numSegs;
growTo.y=crkTip->y+(double)iseg*grow.y/(double)numSegs;
if(fmobj->dflag[0]==4) growTo.y=0.; // force cutting simulation to stay in cut plane at 0
newCrkTip=nextCrack->Propagate(growTo,(int)i,theMaterials[inMat-1]->tractionMat[0]);
}
crkTip = newCrkTip;
if(crkTip!=NULL)
{ // check if crack speed is being controlled
if(theMaterials[inMat-1]->ControlCrackSpeed(crkTip,propTime))
nextPropTime=mtime+propTime;
// crack tip heating (if activated)
if(ConductionTask::active)
conduction->StartCrackTipHeating(crkTip,grow,nextCrack->GetThickness());
}
}
else
{ // when no growth, restore previous growth results
crkTip->potential[0]=crkTip->potential[1];
crkTip->potential[1]=crkTip->potential[2];
crkTip->plastic[0]=crkTip->plastic[1];
crkTip->plastic[1]=crkTip->plastic[2];
crkTip->clength[0]=crkTip->clength[1];
crkTip->clength[1]=crkTip->clength[2];
}
}
}
// next crack
nextCrack=(CrackHeader *)nextCrack->GetNextObject();
}
return nextTask;
}
// Calculate J and K at crack tips
CustomTask *PropagateTask::StepCalculation(void)
{
// if not needed, just exit
if(!doPropCalcs) return nextTask;
CrackHeader *nextCrack;
CrackSegment *crkTip;
double cSize;
int i,inMat;
Vector tipDir,growTo,grow;
int tipElem;
char isAlt[10];
// loop over cracks
nextCrack=firstCrack;
while(nextCrack!=NULL)
{ // each crack tip
for(i=START_OF_CRACK;i<=END_OF_CRACK;i++)
{ // find crack tip and direction
nextCrack->CrackTipAndDirection(i,&crkTip,tipDir);
// crack propagation
inMat=crkTip->tipMatnum;
if(inMat>0)
{ // see if it grows
int shouldGo=theMaterials[inMat-1]->ShouldPropagate(crkTip,tipDir,nextCrack,fmobj->np,0);
isAlt[0] = 0;
if(shouldGo==GROWNOW)
{ nextCrack->SetAllowAlternate(i,false);
}
else if(nextCrack->GetAllowAlternate(i))
{ shouldGo=theMaterials[inMat-1]->ShouldPropagate(crkTip,tipDir,nextCrack,fmobj->np,1);
if(shouldGo==GROWNOW) strcpy(isAlt," (alt)");
}
if(shouldGo==GROWNOW)
{ theResult=GROWNOW;
tipElem=crkTip->planeElemID();
if(fabs(tipDir.x)>fabs(tipDir.y))
cSize=theElements[tipElem]->xmax-theElements[tipElem]->xmin;
else
cSize=theElements[tipElem]->ymax-theElements[tipElem]->ymin;
grow.x=cellsPerPropagationStep*cSize*tipDir.x;
grow.y=cellsPerPropagationStep*cSize*tipDir.y;
// adjust if crossing another crack - adjusts grow is need and returns resulting relative change (in p)
double p = nextCrack->AdjustGrowForCrossing(&grow,crkTip,cSize,&tipDir);
// crack number and tip
archiver->IncrementPropagationCounter();
cout << "# propagation" << isAlt << " crack-tip " << nextCrack->GetNumber() << "-" << i;
// summarize
cout << " at t=" << mtime*UnitsController::Scaling(1.e3)
<< " with J=Jtip+Jzone : " << crkTip->Jint.z*UnitsController::Scaling(1.e-3)
<< " = " << crkTip->Jint.x*UnitsController::Scaling(1.e-3)
<< " + " << (crkTip->Jint.z-crkTip->Jint.x)*UnitsController::Scaling(1.e-3) << endl;
// if jump is .7 or more cells, divide propagation into multiple segments
int iseg,numSegs = 1;
if(p*cellsPerPropagationStep>.7) numSegs= (int)(2*(p*cellsPerPropagationStep+.25));
CrackSegment *newCrkTip = NULL;
for(iseg=1;iseg<=numSegs;iseg++)
{ growTo.x=crkTip->x+(double)iseg*grow.x/(double)numSegs;
growTo.y=crkTip->y+(double)iseg*grow.y/(double)numSegs;
newCrkTip=nextCrack->Propagate(growTo,(int)i,theMaterials[inMat-1]->tractionMat[0]);
}
crkTip = newCrkTip;
if(crkTip!=NULL)
{ // check if crack speed is being controlled
if(theMaterials[inMat-1]->ControlCrackSpeed(crkTip,propTime))
nextPropTime=mtime+propTime;
// crack tip heating (if activated)
if(ConductionTask::active)
conduction->StartCrackTipHeating(crkTip,grow,nextCrack->GetThickness());
}
}
}
}
// next crack
nextCrack=(CrackHeader *)nextCrack->GetNextObject();
}
return nextTask;
}
