private void InitializeCrack()
{
var globalHomogeneousMaterial = HomogeneousElasticMaterial2D.CreateMaterialForPlaneStrain(E, v);
IPropagator propagator = new Propagator(mesh, jIntegralRadiusOverElementSize,
new HomogeneousMaterialAuxiliaryStates(globalHomogeneousMaterial),
new HomogeneousSIFCalculator(globalHomogeneousMaterial),
new MaximumCircumferentialTensileStressCriterion(), new ConstantIncrement2D(growthLength));
CrackMouth = new CartesianPoint(0.0, h / 2);
var crackKink = new CartesianPoint(a, h / 2);
var initialCrack = new PolyLine2D(CrackMouth, crackKink);
initialCrack.UpdateGeometry(-dTheta, da);
//var crackTip = new CartesianPoint(a + da * Math.Cos(dTheta), h/2 - da * Math.Sin(dTheta));
var lsmCrack = new TrackingExteriorCrackLSM(propagator, tipEnrichmentRadius, new RelativeAreaResolver(heavisideTol));
lsmCrack.Mesh = mesh;
// Create enrichments
lsmCrack.CrackBodyEnrichment = new CrackBodyEnrichment2D(lsmCrack);
lsmCrack.CrackTipEnrichments = new CrackTipEnrichments2D(lsmCrack, CrackTipPosition.Single);
if (lsmPlotDirectory != null)
{
lsmCrack.EnrichmentLogger = new EnrichmentLogger(Model, lsmCrack, lsmPlotDirectory);
lsmCrack.LevelSetLogger = new LevelSetLogger(Model, lsmCrack, lsmPlotDirectory);
lsmCrack.LevelSetComparer = new PreviousLevelSetComparer(lsmCrack, lsmPlotDirectory);
}
// Mesh geometry interaction
lsmCrack.InitializeGeometry(initialCrack);
//lsmCrack.UpdateGeometry(-dTheta, da);
this.crack = lsmCrack;
}
public DoubleCantileverBeam()
{
this.material = HomogeneousElasticMaterial2D.CreateMaterialForPlaneStrain(E, v);
this.integration = new IntegrationForCrackPropagation2D(
new RectangularSubgridIntegration2D <XContinuumElement2D>(8, GaussLegendre2D.GetQuadratureWithOrder(2, 2)),
new RectangularSubgridIntegration2D <XContinuumElement2D>(8, GaussLegendre2D.GetQuadratureWithOrder(2, 2)));
this.jIntegration =
new RectangularSubgridIntegration2D <XContinuumElement2D>(8, GaussLegendre2D.GetQuadratureWithOrder(4, 4));
this.beamBoundary = new Rectangular2DBoundary(0, beamLength, 0, beamHeight);
}
private static XContinuumElement2D CreateCrackBodyElement()
{
XNode[] nodes = new XNode[]
{
new XNode(0, 20.0, 0.0),
new XNode(1, 40.0, 0.0),
new XNode(2, 40.0, 20.0),
new XNode(3, 20.0, 20.0),
new XNode(4, 20.0, -40.0),
new XNode(5, 40.0, -40.0),
new XNode(6, 40.0, -20.0),
new XNode(7, 20.0, -20.0)
};
double E = 2e6;
double v = 0.3;
var material = HomogeneousElasticMaterial2D.CreateMaterialForPlaneStrain(E, v);
var integrationStrategy = new IntegrationForCrackPropagation2D(
new RectangularSubgridIntegration2D <XContinuumElement2D>(2, GaussLegendre2D.GetQuadratureWithOrder(2, 2)),
new SimpleIntegration2D());
//var integrationStrategy = new IntegrationForCrackPropagation2D(GaussLegendre2D.GetQuadratureWithOrder(2, 2),
// new RectangularSubgridIntegration2D<XContinuumElement2D>(2, GaussLegendre2D.GetQuadratureWithOrder(2, 2)));
var factory = new XContinuumElement2DFactory(integrationStrategy, integrationStrategy, material);
var bodyElement = factory.CreateElement(0, CellType.Quad4, new XNode[] { nodes[0], nodes[1], nodes[2], nodes[3] });
var blendingElement = factory.CreateElement(1, CellType.Quad4, new XNode[] { nodes[7], nodes[6], nodes[1], nodes[0] });
var tipElement = factory.CreateElement(2, CellType.Quad4, new XNode[] { nodes[4], nodes[5], nodes[6], nodes[7] });
var boundary = new Rectangular2DBoundary(20.0, 40.0, -40.0, 20.0);
var mesh = new SimpleMesh2D <XNode, XContinuumElement2D>(nodes,
new XContinuumElement2D[] { bodyElement, blendingElement, tipElement }, boundary);
var crack = new BasicExplicitCrack2D();
crack.Mesh = mesh;
crack.CrackBodyEnrichment = new CrackBodyEnrichment2D(crack);
crack.CrackTipEnrichments = new CrackTipEnrichments2D(crack, CrackTipPosition.Single);
var point1 = new CartesianPoint(30.0, 20.0);
var point2 = new CartesianPoint(30.0, -30.0);
crack.InitializeGeometry(point1, point2);
crack.UpdateEnrichments();
return(bodyElement);
}
private static (XModel model, IMesh2D <XNode, XContinuumElement2D> mesh) CreateModel(string meshPath)
{
// Mesh generation
var reader = new GmshReader <XNode>(meshPath);
(IReadOnlyList <XNode> nodes, IReadOnlyList <CellConnectivity <XNode> > elementConnectivities) = reader.CreateMesh(
(id, x, y, z) => new XNode(id, x, y, z));
// Nodes
var model = new XModel();
foreach (XNode node in nodes)
{
model.Nodes.Add(node);
}
// Integration rules
var integration = new IntegrationForCrackPropagation2D(
new RectangularSubgridIntegration2D <XContinuumElement2D>(8, GaussLegendre2D.GetQuadratureWithOrder(2, 2)),
new RectangularSubgridIntegration2D <XContinuumElement2D>(8, GaussLegendre2D.GetQuadratureWithOrder(2, 2)));
var jIntegration =
new RectangularSubgridIntegration2D <XContinuumElement2D>(8, GaussLegendre2D.GetQuadratureWithOrder(4, 4));
// Elements
var material = HomogeneousElasticMaterial2D.CreateMaterialForPlaneStrain(2.1E7, 0.3);
var factory = new XContinuumElement2DFactory(integration, jIntegration, material);
var cells = new XContinuumElement2D[elementConnectivities.Count];
for (int e = 0; e < cells.Length; ++e)
{
XContinuumElement2D element = factory.CreateElement(e, CellType.Quad4, elementConnectivities[e].Vertices);
cells[e] = element;
model.Elements.Add(element);
}
// Mesh usable for crack-mesh interaction
//var boundary = new FilletBoundary();
IDomain2DBoundary boundary = null;
model.Boundary = boundary;
var mesh = new BidirectionalMesh2D <XNode, XContinuumElement2D>(model.Nodes, cells, boundary);
return(model, mesh);
}
private void CreateMesh()
{
Model.Subdomains.Add(subdomainID, new XSubdomain(subdomainID));
// Mesh generation
var reader = new GmshReader <XNode>(meshPath);
(IReadOnlyList <XNode> nodes, IReadOnlyList <CellConnectivity <XNode> > elementConnectivities) = reader.CreateMesh(
(id, x, y, z) => new XNode(id, x, y, z));
// Nodes
foreach (XNode node in nodes)
{
Model.Nodes.Add(node);
}
// Integration rules
var integration = new IntegrationForCrackPropagation2D(
new RectangularSubgridIntegration2D <XContinuumElement2D>(8, GaussLegendre2D.GetQuadratureWithOrder(2, 2)),
new RectangularSubgridIntegration2D <XContinuumElement2D>(8, GaussLegendre2D.GetQuadratureWithOrder(2, 2)));
var jIntegration =
new RectangularSubgridIntegration2D <XContinuumElement2D>(8, GaussLegendre2D.GetQuadratureWithOrder(4, 4));
// Elements
var material = HomogeneousElasticMaterial2D.CreateMaterialForPlaneStrain(E, v);
var factory = new XContinuumElement2DFactory(integration, jIntegration, material);
var cells = new XContinuumElement2D[elementConnectivities.Count];
for (int e = 0; e < cells.Length; ++e)
{
XContinuumElement2D element = factory.CreateElement(e, CellType.Quad4, elementConnectivities[e].Vertices);
cells[e] = element;
Model.Elements.Add(element);
Model.Subdomains[subdomainID].Elements.Add(Model.Elements[e]);
}
// Mesh usable for crack-mesh interaction
var boundary = new HolesBoundary();
Model.Boundary = boundary;
Mesh = new BidirectionalMesh2D <XNode, XContinuumElement2D>(Model.Nodes, cells, boundary);
}
/// <summary>
/// The material properties (E, v, E*, v*) must be the same across all elements. The user assumes
/// responsibility for passing a <see cref="HomogeneousElasticMaterial2D"/> that has the same properties as
/// the materials of all other elements of the integration domain.
/// </summary>
/// <param name="globalMaterial">The material properties which must be identical for all elements and this
/// class</param>
public HomogeneousMaterialAuxiliaryStates(HomogeneousElasticMaterial2D globalMaterial)
{
this.material = globalMaterial;
}
/// <summary>
/// The material properties (E, v, E*, v*) must be the same across all elements. The user assumes
/// responsibility for passing a <see cref="HomogeneousElasticMaterial2D"/> that has the same properties as
/// the materials of all other elements of the integration domain.
/// </summary>
/// <param name="globalMaterial">The material properties which must be identical for all elements and this
/// class</param>
public HomogeneousSIFCalculator(HomogeneousElasticMaterial2D globalMaterial)
{
this.equivalentYoungModulus = globalMaterial.HomogeneousEquivalentYoungModulus;
}
