void
Structural2DElement :: giveMaterialOrientationAt(FloatArray &x, FloatArray &y, const FloatArray &lcoords)
{
if ( this->elemLocalCS.isNotEmpty() ) { // User specified orientation
x = {
elemLocalCS.at(1, 1), elemLocalCS.at(2, 1)
};
y = {
-x(1), x(0)
};
} else {
FloatMatrix jac;
this->giveInterpolation()->giveJacobianMatrixAt( jac, lcoords, * this->giveCellGeometryWrapper() );
x.beColumnOf(jac, 1); // This is {dx/dxi, dy/dxi, dz/dxi}
x.normalize();
y = {
-x(1), x(0)
};
}
}
std::vector<std::unique_ptr<EnrichmentItem>> NCPrincipalStress::nucleateEnrichmentItems() {
SpatialLocalizer *octree = this->mpDomain->giveSpatialLocalizer();
XfemManager *xMan = mpDomain->giveXfemManager();
std::vector<std::unique_ptr<EnrichmentItem>> eiList;
// Center coordinates of newly inserted cracks
std::vector<FloatArray> center_coord_inserted_cracks;
// Loop over all elements and all bulk GP.
for(auto &el : mpDomain->giveElements() ) {
int numIR = el->giveNumberOfIntegrationRules();
int csNum = el->giveCrossSection()->giveNumber();
if(csNum == mCrossSectionInd || true) {
for(int irInd = 0; irInd < numIR; irInd++) {
IntegrationRule *ir = el->giveIntegrationRule(irInd);
int numGP = ir->giveNumberOfIntegrationPoints();
for(int gpInd = 0; gpInd < numGP; gpInd++) {
GaussPoint *gp = ir->getIntegrationPoint(gpInd);
// int csNum = gp->giveCrossSection()->giveNumber();
// printf("csNum: %d\n", csNum);
StructuralMaterialStatus *ms = dynamic_cast<StructuralMaterialStatus*>(gp->giveMaterialStatus());
if(ms != NULL) {
const FloatArray &stress = ms->giveTempStressVector();
FloatArray principalVals;
FloatMatrix principalDirs;
StructuralMaterial::computePrincipalValDir(principalVals, principalDirs, stress, principal_stress);
if(principalVals[0] > mStressThreshold) {
// printf("\nFound GP with stress above threshold.\n");
// printf("principalVals: "); principalVals.printYourself();
FloatArray crackNormal;
crackNormal.beColumnOf(principalDirs, 1);
// printf("crackNormal: "); crackNormal.printYourself();
FloatArray crackTangent = {-crackNormal(1), crackNormal(0)};
crackTangent.normalize();
// printf("crackTangent: "); crackTangent.printYourself();
// Create geometry
FloatArray pc = {gp->giveGlobalCoordinates()(0), gp->giveGlobalCoordinates()(1)};
// printf("Global coord: "); pc.printYourself();
FloatArray ps = pc;
ps.add(-0.5*mInitialCrackLength, crackTangent);
FloatArray pe = pc;
pe.add(0.5*mInitialCrackLength, crackTangent);
if(mCutOneEl) {
// If desired, ensure that the crack cuts exactly one element.
Line line(ps, pe);
std::vector<FloatArray> intersecPoints;
// line.computeIntersectionPoints(el.get(), intersecPoints);
for ( int i = 1; i <= el->giveNumberOfDofManagers(); i++ ) {
// int n1 = i;
// int n2 = 0;
// if ( i < el->giveNumberOfDofManagers() ) {
// n2 = i + 1;
// } else {
// n2 = 1;
// }
// const FloatArray &p1 = *(el->giveDofManager(n1)->giveCoordinates());
// const FloatArray &p2 = *(el->giveDofManager(n2)->giveCoordinates());
}
// printf("intersecPoints.size(): %lu\n", intersecPoints.size());
if(intersecPoints.size() == 2) {
ps = std::move(intersecPoints[0]);
pe = std::move(intersecPoints[1]);
}
else {
OOFEM_ERROR("intersecPoints.size() != 2")
}
}
FloatArray points = {ps(0), ps(1), pc(0), pc(1), pe(0), pe(1)};
// double diffX = 0.5*(ps(0) + pe(0)) - pc(0);
// printf("diffX: %e\n", diffX);
// double diffY = 0.5*(ps(1) + pe(1)) - pc(1);
// printf("diffY: %e\n", diffY);
// TODO: Check if nucleation is allowed, by checking for already existing cracks close to the GP.
// Idea: Nucleation is not allowed if we are within an enriched element. In this way, branching is not
// completely prohibited, but we avoid initiating multiple similar cracks.
bool insertionAllowed = true;
Element *el_s = octree->giveElementContainingPoint(ps);
if(el_s) {
if( xMan->isElementEnriched(el_s) ) {
insertionAllowed = false;
}
}
Element *el_c = octree->giveElementContainingPoint(pc);
if(el_c) {
if( xMan->isElementEnriched(el_c) ) {
insertionAllowed = false;
}
}
Element *el_e = octree->giveElementContainingPoint(pe);
if(el_e) {
if( xMan->isElementEnriched(el_e) ) {
insertionAllowed = false;
}
}
for(const auto &x: center_coord_inserted_cracks) {
if( x.distance(pc) < 2.0*mInitialCrackLength) {
insertionAllowed = false;
break;
printf("Preventing insertion.\n");
}
}
if(insertionAllowed) {
int n = xMan->giveNumberOfEnrichmentItems() + 1;
std::unique_ptr<Crack> crack = std::make_unique<Crack>(n, xMan, mpDomain);
// Geometry
std::unique_ptr<BasicGeometry> geom = std::make_unique<PolygonLine>();
geom->insertVertexBack(ps);
geom->insertVertexBack(pc);
geom->insertVertexBack(pe);
crack->setGeometry(std::move(geom));
// Enrichment function
EnrichmentFunction *ef = new HeavisideFunction(1, mpDomain);
crack->setEnrichmentFunction(ef);
// Enrichment fronts
// EnrichmentFront *efStart = new EnrFrontLinearBranchFuncOneEl();
EnrichmentFront *efStart = new EnrFrontCohesiveBranchFuncOneEl();
crack->setEnrichmentFrontStart(efStart);
// EnrichmentFront *efEnd = new EnrFrontLinearBranchFuncOneEl();
EnrichmentFront *efEnd = new EnrFrontCohesiveBranchFuncOneEl();
crack->setEnrichmentFrontEnd(efEnd);
///////////////////////////////////////
// Propagation law
// Options
// double radius = 0.5*mInitialCrackLength, angleInc = 10.0, incrementLength = 0.5*mInitialCrackLength, hoopStressThreshold = 0.0;
// bool useRadialBasisFunc = true;
// PLHoopStressCirc *pl = new PLHoopStressCirc();
// pl->setRadius(radius);
// pl->setAngleInc(angleInc);
// pl->setIncrementLength(incrementLength);
// pl->setHoopStressThreshold(hoopStressThreshold);
// pl->setUseRadialBasisFunc(useRadialBasisFunc);
// PLDoNothing *pl = new PLDoNothing();
PLMaterialForce *pl = new PLMaterialForce();
pl->setRadius(mMatForceRadius);
pl->setIncrementLength(mIncrementLength);
// pl->setIncrementLength(0.25);
// pl->setCrackPropThreshold(0.25);
pl->setCrackPropThreshold(mCrackPropThreshold);
crack->setPropagationLaw(pl);
crack->updateDofIdPool();
center_coord_inserted_cracks.push_back(pc);
eiList.push_back( std::unique_ptr<EnrichmentItem>(std::move(crack)) );
// printf("Nucleating a crack in NCPrincipalStress::nucleateEnrichmentItems.\n");
// printf("el->giveGlobalNumber(): %d\n", el->giveGlobalNumber() );
// We only introduce one crack per element in a single time step.
break;
}
}
}
}
}
} // If correct csNum
}
