/// <inheritdoc/>
public Matrix CalcLocalStiffnessMatrix(Element targetElement)
{
//edit
var b = GetBMatrixAt(targetElement, 0, 0, 0);
var d = GetDMatrixAt(targetElement, 0, 0, 0);
var k = b.Transpose() * d * b;
var v = GetJMatrixAt(targetElement, 0, 0, 0).Determinant() / 6.0;
k.Scale(v);
return(k);
return(ElementHelperExtensions.CalcLocalKMatrix_Tetrahedron(this, targetElement));
}
/// <inheritdoc/>
public Matrix CalcLocalStiffnessMatrix(Element targetElement)
{
/**/
var tetra = targetElement as TetrahedronElement;
var X = (Matrix)targetElement.AllocateFromPool(4, 4);
{
var ps = tetra.Nodes.Select(i => i.Location).ToArray();
{//9.11
X.SetRow(0, new double[] { 1, 1, 1, 1 });
X.SetRow(1, new double[] { ps[0].X, ps[1].X, ps[2].X, ps[3].X });
X.SetRow(2, new double[] { ps[0].Y, ps[1].Y, ps[2].Y, ps[3].Y });
X.SetRow(3, new double[] { ps[0].Z, ps[1].Z, ps[2].Z, ps[3].Z });
}
}
/**/
//edit
var b = GetBMatrixAt(targetElement, 0, 0, 0);
var d = GetDMatrixAt(targetElement, 0, 0, 0);
var k = (b.Transpose() * d) * b;
var v = X.Determinant() / 6.0;
if (v < 0)
{
throw new Exception();
}
k.Scale(v);
return(k);
return(ElementHelperExtensions.CalcLocalKMatrix_Tetrahedron(this, targetElement));
}