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 :: giveEffectiveMaterialStiffnessMatrix(FloatMatrix &answer,
MatResponseForm form,
MatResponseMode rMode, GaussPoint *gp,
TimeStep *atTime)
//
// returns effective material stiffness matrix in full form
// for gp stress strain mode
//
{
RCM2MaterialStatus *status = ( RCM2MaterialStatus * ) this->giveStatus(gp);
StructuralMaterial *lMat = static_cast< StructuralMaterial * >( this->giveLinearElasticMaterial() );
int numberOfActiveCracks = status->giveNumberOfTempActiveCracks();
int i, j, indi, indj, ii, jj;
double G, princStressDis, princStrainDis;
FloatMatrix de, invDe, compliance, dcr, d, df, t, tt, tempCrackDirs;
FloatArray principalStressVector, principalStrainVector;
IntArray mask;
if ( ( rMode == ElasticStiffness ) || ( numberOfActiveCracks == 0 ) ) {
lMat->giveCharacteristicMatrix(answer, form, rMode, gp, atTime);
return;
}
// this->updateActiveCrackMap(gp) must be done after restart.
this->updateActiveCrackMap(gp);
status->giveTempCrackDirs(tempCrackDirs);
this->giveNormalElasticStiffnessMatrix(de, ReducedForm, rMode, gp, atTime,
tempCrackDirs);
invDe.beInverseOf(de);
this->giveCrackedStiffnessMatrix(dcr, rMode, gp, atTime);
this->giveStressStrainMask( mask, ReducedForm, gp->giveMaterialMode() );
compliance.resize( mask.giveSize(), mask.giveSize() );
// we will set
// first we set compliances for normal streses in
// local coordinate system defined by crackplane
for ( i = 1; i <= 3; i++ ) {
if ( ( indi = this->giveStressStrainComponentIndOf(FullForm, gp->giveMaterialMode(), i) ) ) {
for ( j = 1; j <= 3; j++ ) {
if ( ( indj = this->giveStressStrainComponentIndOf(FullForm, gp->giveMaterialMode(), j) ) ) {
compliance.at(indi, indj) += invDe.at(i, j);
}
}
if ( status->isCrackActive(i) ) {
if ( dcr.at(i, i) <= 1.e-8 ) {
compliance.at(indi, indi) *= rcm2_BIGNUMBER;
} else {
compliance.at(indi, indi) += 1. / dcr.at(i, i);
}
}
}
}
status->getPrincipalStressVector(principalStressVector);
status->getPrincipalStrainVector(principalStrainVector);
// now remain to set shears
G = this->give(pscm_G, gp);
for ( i = 4; i <= 6; i++ ) {
if ( ( indi = this->giveStressStrainComponentIndOf(FullForm, gp->giveMaterialMode(), i) ) ) {
if ( i == 4 ) {
ii = 2;
jj = 3;
} else if ( i == 5 ) {
ii = 1;
jj = 3;
} else {
ii = 1;
jj = 2;
}
princStressDis = principalStressVector.at(ii) -
principalStressVector.at(jj);
princStrainDis = principalStrainVector.at(ii) -
principalStrainVector.at(jj);
if ( fabs(princStrainDis) < rcm_SMALL_STRAIN ) {
compliance.at(indi, indi) = 1. / G;
} else if ( fabs(princStressDis) < 1.e-8 ) {
compliance.at(indi, indi) = rcm2_BIGNUMBER;
} else {
compliance.at(indi, indi) = 2 * princStrainDis / princStressDis;
}
}
}
// now we invert compliance to get stiffness in reduced space
d.beInverseOf(compliance);
// delete compliance;
//
// now let d to grow to Full Format
//
this->giveStressStrainMask( mask, ReducedForm, gp->giveMaterialMode() );
df.beSubMatrixOfSizeOf(d, mask, 6);
//
// final step - transform stiffnes to global c.s
//
this->giveStressVectorTranformationMtrx(t, tempCrackDirs, 1);
tt.beTranspositionOf(t);
df.rotatedWith(tt);
if ( form == FullForm ) {
answer = df;
} else { // reduced form asked
this->giveStressStrainMask( mask, FullForm, gp->giveMaterialMode() );
answer.beSubMatrixOf(df, mask);
}
}
void
RCM2Material :: checkForNewActiveCracks(IntArray &answer, GaussPoint *gp,
const FloatArray &crackStrain,
const FloatArray &princStressVector,
FloatArray &crackStressVector,
const FloatArray &princStrainVector)
//
// returns int_array flag showing if some crack
// is newly activated or
// closed crack is reopened
// return 0 if no crack is activated or reactivated.
// modifies crackStressVector for newly activated crack.
//
{
double initStress, Le = 0.0;
int i, j, upd, activationFlag = 0;
RCM2MaterialStatus *status = ( RCM2MaterialStatus * ) this->giveStatus(gp);
FloatArray localStress;
FloatMatrix tempCrackDirs;
IntArray crackMap;
answer.resize(3);
answer.zero();
status->giveCrackMap(crackMap);
localStress = princStressVector;
//
// local stress is updated according to reached local crack strain
//
for ( i = 1; i <= 3; i++ ) { // loop over each possible crack plane
// test previous status of each possible crack plane
upd = 0;
if ( ( crackMap.at(i) == 0 ) &&
( this->giveStressStrainComponentIndOf(FullForm, gp->giveMaterialMode(), i) ) ) {
if ( status->giveTempMaxCrackStrain(i) > 0. ) {
// if (status->giveTempCrackStatus()->at(i) != pscm_NONE) {
//
// previously cracked direction
//
initStress = 0.;
} else {
// newer cracked, so we compute principal stresses
// and compare them with reduced tension strength
// as a criterion for crack initiation
FloatArray crackPlaneNormal(3);
status->giveTempCrackDirs(tempCrackDirs);
for ( j = 1; j <= 3; j++ ) {
crackPlaneNormal.at(j) = tempCrackDirs.at(j, i);
}
// Le = gp->giveElement()->giveCharacteristicLenght (gp, &crackPlaneNormal);
Le = this->giveCharacteristicElementLenght(gp, crackPlaneNormal);
initStress = this->computeStrength(gp, Le);
upd = 1;
}
if ( localStress.at(i) > initStress ) {
crackStressVector.at(i) = initStress;
answer.at(i) = 1;
activationFlag = 1;
if ( upd ) {
this->updateStatusForNewCrack(gp, i, Le);
}
}
} // end of tested crack
} // end of loop over are possible directions
if ( activationFlag ) {
return;
}
answer.resize(0);
}
