/// <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 GetNMatrixAt(Element targetElement, params double[] isoCoords)
{
var xi = isoCoords[0];
if (xi < -1 || xi > 1)
{
throw new ArgumentOutOfRangeException(nameof(isoCoords));
}
var bar = targetElement as BarElement;
if (bar == null)
{
throw new Exception();
}
var L = (bar.EndNode.Location - bar.StartNode.Location).Length;
var n1 = 1 / 4.0 * (1 - xi) * (1 - xi) * (2 + xi); //[slope(-1) = slope(1) = val(1) = 0, val(-1) = 1]
var m1 = L / 8.0 * (1 - xi) * (1 - xi) * (xi + 1); //[slope(-1) = 1, slope(1) = val(1) = val(-1) = 0]
var n2 = 1 / 4.0 * (1 + xi) * (1 + xi) * (2 - xi); //[val(1) = 1, slope(-1) = slope(1) = val(-1) = 0]
var m2 = L / 8.0 * (1 + xi) * (1 + xi) * (xi - 1); //[slope(1) = 1, slope(-1) = val(1) = val(-1) = 0]
var buf = new Matrix(1, 4);
double[] arr;
if (_direction == BeamDirection.Z)
{
arr = new double[] { n1, -m1, n2, -m2 }
}
;
else
{
arr = new double[] { n1, m1, n2, m2 }
};
buf.FillRow(0, arr);
ElementHelperExtensions.RemoveReleasedMembers_bar(this, targetElement, buf);
return(buf);
}
/// <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));
}
/// <inheritdoc/>
public Matrix CalcLocalCMatrix(Element targetElement)
{
return(ElementHelperExtensions.CalcLocalCMatrix_Bar(this, targetElement));
}
/// <inheritdoc/>
public Matrix CalcLocalMMatrix(Element targetElement)
{
var buf = ElementHelperExtensions.CalcLocalMMatrix_Bar(this, targetElement);
return(buf);
}
public Matrix CalcLocalStiffnessMatrix(Element targetElement)
{
var buf = ElementHelperExtensions.CalcLocalKMatrix_Triangle(this, targetElement);
return(buf);
}
/// <inheritdoc/>
public Matrix CalcLocalKMatrix(Element targetElement)
{
return(ElementHelperExtensions.CalcLocalKMatrix_Triangle(this, targetElement));
}
