void
RCM2Material :: giveRealStressVector(FloatArray &answer, MatResponseForm form, GaussPoint *gp,
const FloatArray &totalStrain,
TimeStep *atTime)
//
// returns real stress vector in 3d stress space of receiver according to
// previous level of stress and current
// strain increment, the only way, how to correctly update gp records
//
{
FloatArray princStress, reducedStressVector, crackStrain, reducedAnswer;
FloatArray reducedTotalStrainVector, principalStrain, strainVector;
FloatMatrix tempCrackDirs;
RCM2MaterialStatus *status = ( RCM2MaterialStatus * ) this->giveStatus(gp);
StructuralCrossSection *crossSection = ( StructuralCrossSection * ) gp->giveElement()->giveCrossSection();
this->initTempStatus(gp);
this->initGpForNewStep(gp);
// subtract stress independent part
// note: eigenStrains (temperature) is not contained in mechanical strain stored in gp
// therefore it is necessary to subtract always the total eigen strain value
this->giveStressDependentPartOfStrainVector(reducedTotalStrainVector, gp, totalStrain, atTime, VM_Total);
//
crossSection->giveFullCharacteristicVector(strainVector, gp, reducedTotalStrainVector);
status->giveTempCrackDirs(tempCrackDirs);
this->computePrincipalValDir(principalStrain, tempCrackDirs,
strainVector,
principal_strain);
this->giveRealPrincipalStressVector3d(princStress, gp, principalStrain, tempCrackDirs, atTime);
princStress.resize(6);
status->giveTempCrackDirs(tempCrackDirs);
this->transformStressVectorTo(answer, tempCrackDirs, princStress, 1);
status->letTempStrainVectorBe(totalStrain);
crossSection->giveReducedCharacteristicVector(reducedStressVector, gp, answer);
status->letTempStressVectorBe(reducedStressVector);
status->giveCrackStrainVector(crackStrain);
this->updateCrackStatus(gp, crackStrain);
if ( form == FullForm ) {
return;
}
crossSection->giveReducedCharacteristicVector(reducedAnswer, gp, answer);
answer = reducedAnswer;
}
void
RCM2Material :: giveRealPrincipalStressVector3d(FloatArray &answer, GaussPoint *gp,
FloatArray &principalStrain,
FloatMatrix &tempCrackDirs,
TimeStep *atTime)
//
// returns real principal stress vector in 3d stress space of receiver according to
// previous level of stress and current
// strain increment, the only way, how to correctly update gp records
// updates principal strain and stress of the receiver's status.
//
{
int i, iter, ind;
double maxErr;
FloatArray crackStrainVector, reducedTotalStrainVector;
FloatArray strainIncrement, crackStrainIterativeIncrement;
FloatArray prevPrincipalStrain;
FloatArray dSigma;
FloatArray elastStrain, sigmaEl, sigmaCr(3);
FloatArray fullDSigma;
IntArray activatedCracks, crackMapping;
FloatMatrix dcr, de, decr, fullDecr, crackDirs;
RCM2MaterialStatus *status = ( RCM2MaterialStatus * ) this->giveStatus(gp);
/*
* if (status -> giveStressVector() == NULL) status->letStressVectorBe(new FloatArray(this->giveSizeOfReducedStressStrainVector(gp->giveMaterialMode())));
* if (status -> giveStrainVector() == NULL) status->letStrainVectorBe(new FloatArray(this->giveSizeOfReducedStressStrainVector(gp->giveMaterialMode())));
* // if (status -> givePlasticStrainVector() == NULL) status->letPlasticStrainVectorBe(new FloatArray(6));
* if (status -> giveStressIncrementVector() == NULL) status->letStressIncrementVectorBe(new FloatArray(this->giveSizeOfReducedStressStrainVector(gp->giveMaterialMode())));
* if (status -> giveStrainIncrementVector() == NULL) status->letStrainIncrementVectorBe(new FloatArray(this->giveSizeOfReducedStressStrainVector(gp->giveMaterialMode())));
* // if (status -> givePlasticStrainIncrementVector() == NULL) status->letPlasticStrainIncrementVectorBe(new FloatArray(6));
*/
/*
* // totalStressVector = gp -> giveStressVector()->GiveCopy();
* reducedTotalStrainVector = status -> giveStrainVector();
* reducedTotalStrainVector.add(fullStrainIncrement);
* crossSection->giveFullCharacteristicVector(totalStrainVector, gp, reducedTotalStrainVector);
* //delete reducedTotalStrainVector;
* // plasticStrainVector = status -> givePlasticStrainVector()->GiveCopy();
*
*
* // already cracked - next directions are determined
* // according to principal strain directions
* status->giveTempCrackDirs(tempCrackDirs);
* this->computePrincipalValDir (principalStrain, tempCrackDirs,
* totalStrainVector,
* principal_strain);
* status->letTempCrackDirsBe (tempCrackDirs);
*/
status->giveCrackStrainVector(crackStrainVector); // local one
status->giveCrackDirs(crackDirs);
if ( principalStrain.containsOnlyZeroes() ) {
// keep old principal values
status->letTempCrackDirsBe(crackDirs);
} else {
this->sortPrincDirAndValCloseTo(& principalStrain,
& tempCrackDirs, & crackDirs);
status->letTempCrackDirsBe(tempCrackDirs);
}
// compute de in local system
// for iso materials no transformation if stiffness required
//
// local strain increment
status->givePrevPrincStrainVector(prevPrincipalStrain);
strainIncrement.beDifferenceOf(principalStrain, prevPrincipalStrain);
status->letPrincipalStrainVectorBe(principalStrain);
this->giveNormalElasticStiffnessMatrix(de, FullForm, TangentStiffness,
gp, atTime, tempCrackDirs);
//
// construct mapping matrix of active cracks
// this mapping will dynamically change as
// some crack can unlo or reload
//
this->updateActiveCrackMap(gp);
status->giveCrackMap(crackMapping);
// start iteration until stress computed from elastic increment
// is equal to stress computed from cracking strain increment
// we do this computation in reduced stress strain space
dSigma.resize(0);
for ( iter = 1; iter <= 20; iter++ ) {
//
// first check if already cracked
//
if ( status->giveNumberOfTempActiveCracks() ) {
// active crack exist
this->giveCrackedStiffnessMatrix(dcr, TangentStiffness, gp, atTime);
fullDecr = de;
fullDecr.add(dcr);
decr.beSubMatrixOf(fullDecr, crackMapping);
if ( dSigma.giveSize() == 0 ) {
fullDSigma.beProductOf(de, strainIncrement);
dSigma.beSubArrayOf(fullDSigma, crackMapping);
}
decr.solveForRhs(dSigma, crackStrainIterativeIncrement);
for ( i = 1; i <= 3; i++ ) {
if ( ( ind = crackMapping.at(i) ) ) {
crackStrainVector.at(i) += crackStrainIterativeIncrement.at(ind);
}
}
// check for crack closing, updates also cracking map
this->checkIfClosedCracks(gp, crackStrainVector, crackMapping);
// elastic strain component
elastStrain.beDifferenceOf(principalStrain, crackStrainVector);
sigmaEl.beProductOf(de, elastStrain);
// Stress in cracks
for ( i = 1; i <= 3; i++ ) {
if ( crackMapping.at(i) ) {
sigmaCr.at(i) = giveNormalCrackingStress(gp, crackStrainVector.at(i), i);
}
}
// update status
status->letCrackStrainVectorBe(crackStrainVector);
} else {
//
// no active crack exist - elastic behaviour
//
elastStrain.beDifferenceOf(principalStrain, crackStrainVector);
sigmaEl.beProductOf(de, elastStrain);
sigmaCr.zero();
}
// check for new cracks
// and update crack map if necessary
// when we update map, we need to add new crack at end
// because sigmaCr is build
this->checkForNewActiveCracks(activatedCracks, gp, crackStrainVector,
sigmaEl, sigmaCr, principalStrain);
if ( activatedCracks.giveSize() ) {
// update crack map also
this->updateActiveCrackMap(gp, & activatedCracks);
status->giveCrackMap(crackMapping); // update crackMap
}
//
// compute unbalanced stress
// dSigma = sigmaEl - sigmaCr for active cracks
fullDSigma = sigmaEl;
fullDSigma.subtract(sigmaCr);
dSigma.beSubArrayOf(fullDSigma, crackMapping);
// find max error in dSigma
// if max err < allovedErr -> stop iteration
// allowed Err is computed relative to Ft;
// check only for active cracks
maxErr = 0.;
for ( i = 1; i <= dSigma.giveSize(); i++ ) {
if ( fabs( dSigma.at(i) ) > maxErr ) {
maxErr = fabs( dSigma.at(i) );
}
}
if ( maxErr < rcm_STRESSRELERROR * this->give(pscm_Ft, gp) ) {
status->letPrincipalStressVectorBe(sigmaEl);
answer = sigmaEl;
return;
}
} // loop
// convergence not reached
_error("GiveRealStressVector3d - convergence not reached");
}