void
GradDpElement :: computeStiffnessMatrix_uu(FloatMatrix &answer, MatResponseMode rMode, TimeStep *tStep)
{
NLStructuralElement *elem = this->giveNLStructuralElement();
StructuralCrossSection *cs = elem->giveStructuralCrossSection();
FloatMatrix B, D, DB;
int nlGeo = elem->giveGeometryMode();
bool matStiffSymmFlag = elem->giveCrossSection()->isCharacteristicMtrxSymmetric(rMode);
answer.clear();
for ( GaussPoint *gp: *elem->giveIntegrationRule(0) ) {
GradDpMaterialExtensionInterface *dpmat = dynamic_cast< GradDpMaterialExtensionInterface * >(
cs->giveMaterialInterface(GradDpMaterialExtensionInterfaceType, gp) );
if ( !dpmat ) {
OOFEM_ERROR("Material doesn't implement the required DpGrad interface!");
}
if ( nlGeo == 0 ) {
elem->computeBmatrixAt(gp, B);
} else if ( nlGeo == 1 ) {
if ( elem->domain->giveEngngModel()->giveFormulation() == AL ) {
elem->computeBmatrixAt(gp, B);
} else {
elem->computeBHmatrixAt(gp, B);
}
}
dpmat->givePDGradMatrix_uu(D, rMode, gp, tStep);
double dV = elem->computeVolumeAround(gp);
DB.beProductOf(D, B);
if ( matStiffSymmFlag ) {
answer.plusProductSymmUpper(B, DB, dV);
} else {
answer.plusProductUnsym(B, DB, dV);
}
}
if ( elem->domain->giveEngngModel()->giveFormulation() == AL ) {
FloatMatrix initialStressMatrix;
elem->computeInitialStressMatrix(initialStressMatrix, tStep);
answer.add(initialStressMatrix);
}
if ( matStiffSymmFlag ) {
answer.symmetrized();
}
}
void
GradDpElement :: computeStiffnessMatrix(FloatMatrix &answer, MatResponseMode rMode, TimeStep *tStep)
{
//set displacement and nonlocal location array
this->setDisplacementLocationArray();
this->setNonlocalLocationArray();
NLStructuralElement *elem = this->giveNLStructuralElement();
StructuralCrossSection *cs = elem->giveStructuralCrossSection();
FloatMatrix B, D, DB;
FloatMatrix DkuB, Dku;
FloatArray Nk;
FloatMatrix SNk, gPSigma;
FloatMatrix lStiff;
FloatMatrix Bk, LBk;
FloatMatrix answer_uu, answer_ku, answer_uk, answer_kk;
int nlGeo = elem->giveGeometryMode();
bool matStiffSymmFlag = elem->giveCrossSection()->isCharacteristicMtrxSymmetric(rMode);
for ( auto &gp : *elem->giveIntegrationRule(0) ) {
GradDpMaterialExtensionInterface *dpmat = dynamic_cast< GradDpMaterialExtensionInterface * >(
cs->giveMaterialInterface(GradDpMaterialExtensionInterfaceType, gp) );
if ( !dpmat ) {
OOFEM_ERROR("Material doesn't implement the required DpGrad interface!");
}
double dV = elem->computeVolumeAround(gp);
if ( nlGeo == 0 ) {
elem->computeBmatrixAt(gp, B);
} else if ( nlGeo == 1 ) {
if ( elem->domain->giveEngngModel()->giveFormulation() == AL ) {
elem->computeBmatrixAt(gp, B);
} else {
elem->computeBHmatrixAt(gp, B);
}
}
this->computeNkappaMatrixAt(gp, Nk);
this->computeBkappaMatrixAt(gp, Bk);
dpmat->givePDGradMatrix_uu(D, rMode, gp, tStep);
dpmat->givePDGradMatrix_ku(Dku, rMode, gp, tStep);
dpmat->givePDGradMatrix_uk(gPSigma, rMode, gp, tStep);
dpmat->givePDGradMatrix_kk(lStiff, rMode, gp, tStep);
/////////////////////////////////////////////////////////////////// uu:
DB.beProductOf(D, B);
if ( matStiffSymmFlag ) {
answer_uu.plusProductSymmUpper(B, DB, dV);
} else {
answer_uu.plusProductUnsym(B, DB, dV);
}
//////////////////////////////////////////////////////////////////////// ku:
DkuB.beProductOf(Dku, B);
answer_ku.plusProductUnsym(Nk, DkuB, -dV);
if ( dpmat->giveAveragingType() == 2 ) {
double dl1, dl2, dl3;
FloatMatrix LDB;
FloatMatrix GkLDB, MGkLDB;
FloatMatrix M22, M12;
FloatMatrix dL1(1, 3), dL2(1, 3), dLdS;
FloatArray Gk, n1, n2;
dpmat->givePDGradMatrix_LD(dLdS, rMode, gp, tStep);
this->computeNonlocalGradient(Gk, gp, tStep);
dl1 = dLdS.at(3, 3);
dl2 = dLdS.at(4, 4);
dl3 = dLdS.at(5, 5);
n1 = {dLdS.at(1, 1), dLdS.at(2, 1)};
n2 = {dLdS.at(1, 2), dLdS.at(2, 2)};
// first term Bk^T M22 G L1 D B
// M22 = n2 \otimes n2
M22.plusDyadUnsym(n2, n2, 1.);
// dL1
dL1.at(1, 1) = dl1 * n1.at(1) * n1.at(1) + dl2 * n2.at(1) * n2.at(1);
dL1.at(1, 2) = dl1 * n1.at(2) * n1.at(2) + dl2 * n2.at(2) * n2.at(2);
dL1.at(1, 3) = dl1 * n1.at(1) * n1.at(2) + dl2 * n2.at(1) * n2.at(2);
LDB.beProductOf(dL1, DB);
GkLDB.beProductOf(Gk, LDB);
MGkLDB.beProductOf(M22, GkLDB);
answer.plusProductUnsym(Bk, MGkLDB, dV);
// M12 + M21 = n1 \otimes n2 + n2 \otimes n1
M12.plusDyadUnsym(n1, n2, 1.);
M12.plusDyadUnsym(n2, n1, 1.);
//dL2
dL2.at(1, 1) = dl3 * ( n1.at(1) * n2.at(1) + n1.at(1) * n2.at(1) );
dL2.at(1, 2) = dl3 * ( n1.at(2) * n2.at(2) + n1.at(2) * n2.at(2) );
dL2.at(1, 3) = dl3 * ( n1.at(2) * n2.at(1) + n1.at(1) * n2.at(2) );
// Bk * ((M12 * L2 + M22 * L1) * DB)
LDB.beProductOf(dL2, DB);
GkLDB.beProductOf(Gk, LDB);
MGkLDB.beProductOf(M12, GkLDB);
answer.plusProductUnsym(Bk, MGkLDB, dV);
}
//////////////////////////////////////////////////////////////////////// uk:
SNk.beProductOf(gPSigma, Nk);
answer_uk.plusProductUnsym(B, SNk, -dV); // uk
/////////////////////////////////////////////////////////////////////// kk:
answer_kk.plusProductUnsym(Nk, Nk, dV);
if ( dpmat->giveAveragingType() == 0 || dpmat->giveAveragingType() == 1 ) {
double l = lStiff.at(1, 1);
answer_kk.plusProductUnsym(Bk, Bk, l * l * dV);
} else if ( dpmat->giveAveragingType() == 2 ) {
LBk.beProductOf(lStiff, Bk);
answer_kk.plusProductUnsym(Bk, LBk, dV);
}
}
if ( elem->domain->giveEngngModel()->giveFormulation() == AL ) {
FloatMatrix initialStressMatrix;
elem->computeInitialStressMatrix(initialStressMatrix, tStep);
answer_uu.add(initialStressMatrix);
}
if ( matStiffSymmFlag ) {
answer_uu.symmetrized();
}
answer.resize(totalSize, totalSize);
answer.zero();
answer.assemble(answer_uu, locU);
answer.assemble(answer_uk, locU, locK);
answer.assemble(answer_ku, locK, locU);
answer.assemble(answer_kk,locK);
}