//TODO: Either work with Tensor class or double[]
private IReadOnlyList <Tensor2D> ElementNodalTensorsExtrapolation(XContinuumElement2D element,
Vector freeDisplacements, Vector constrainedDisplacements, IOutputField field)
{
Vector standardDisplacements = dofOrderer.ExtractDisplacementVectorOfElementFromGlobal(element,
freeDisplacements, constrainedDisplacements);
Vector enrichedDisplacements =
dofOrderer.ExtractEnrichedDisplacementsOfElementFromGlobal(element, freeDisplacements);
IReadOnlyList <NaturalPoint> gaussPoints = element.GaussPointExtrapolation.Quadrature.IntegrationPoints;
var gpTensors = new Tensor2D[gaussPoints.Count];
for (int i = 0; i < gaussPoints.Count; ++i)
{
gpTensors[i] =
field.EvaluateAt(element, gaussPoints[i], standardDisplacements, enrichedDisplacements);
}
return(element.GaussPointExtrapolation.ExtrapolateTensorFromGaussPointsToNodes(gpTensors, element.Interpolation));
}
// Computes stresses directly at the nodes. The other approach is to compute them at Gauss points and then extrapolate
private IReadOnlyList <Tensor2D> ElementNodalTensorsDirectly(XContinuumElement2D element,
Vector freeDisplacements, Vector constrainedDisplacements, IOutputField field)
{
Vector standardDisplacements = dofOrderer.ExtractDisplacementVectorOfElementFromGlobal(element,
freeDisplacements, constrainedDisplacements);
Vector enrichedDisplacements =
dofOrderer.ExtractEnrichedDisplacementsOfElementFromGlobal(element, freeDisplacements);
IReadOnlyList <NaturalPoint> naturalNodes = element.Interpolation.NodalNaturalCoordinates;
var nodalTensors = new Tensor2D[element.Nodes.Count];
for (int i = 0; i < element.Nodes.Count; ++i)
{
nodalTensors[i] =
field.EvaluateAt(element, naturalNodes[i], standardDisplacements, enrichedDisplacements);
}
return(nodalTensors);
}
