/*
* private Matrix GetVariableMatrixOnElement(FiniteElement element, double ksi, double eta)
* {
* Matrix VariableMatrix = new Matrix(4, 4);
* Vector du = previousRes.DU(ksi, eta, element);
* double d1u1 = du[0];
* double d3u3 = du[1];
* double d3u1 = du[2];
* double d1u3 = du[3];
*
* VariableMatrix[0, 0] = 1.5 * M1 * d1u1 + 0.5 * M2 * d3u3;
* VariableMatrix[0, 1] = M2 * d3u3 + M2 * d1u1;
* VariableMatrix[0, 2] = M2 * d3u1 + G13 * (2 * d3u1 + d1u3);
* VariableMatrix[0, 3] = M1 * d1u3 + G13 * d1u1;
*
* VariableMatrix[1, 1] = 1.5 * M3 * d3u3 + 0.5 * M2 * d1u1;
* VariableMatrix[1, 2] = M3 * d3u1 + G13 * d1u3;
* VariableMatrix[1, 3] = M2 * d1u3 + G13 * (2 * d1u3 + d3u1);
*
* VariableMatrix[2, 2] = 0.5 * M3 * d3u3 + (0.5 * M2 + G13)*d1u1;
* VariableMatrix[2, 3] = G13 * (d3u3 + d1u1);
*
* VariableMatrix[3, 3] = 0.5 * M1 * d1u1 + (0.5 * M2 + G13) * d3u3;
*
* return VariableMatrix;
* }*/
private Matrix GetLocalDerivativeMatrix(FiniteElement element, double ksi, double eta)
{
Matrix LocalDerivativeMatrix = new Matrix(8, 4);
Matrix gradNksieta = new Matrix(2, 4);
gradNksieta[0, 0] = (eta - 1) * 0.25;
gradNksieta[1, 0] = (ksi - 1) * 0.25;
gradNksieta[0, 1] = (1 - eta) * 0.25;
gradNksieta[1, 1] = (-ksi - 1) * 0.25;
gradNksieta[0, 2] = (eta + 1) * 0.25;
gradNksieta[1, 2] = (ksi + 1) * 0.25;
gradNksieta[0, 3] = (-eta - 1) * 0.25;
gradNksieta[1, 3] = (1 - ksi) * 0.25;
Jacobian J = new Jacobian();
J.Element = element;
Matrix gradN = J.GetInverseJacobian(ksi, eta) * gradNksieta;
LocalDerivativeMatrix[0, 0] = LocalDerivativeMatrix[1, 3] = gradN[0, 0];
LocalDerivativeMatrix[2, 0] = LocalDerivativeMatrix[3, 3] = gradN[0, 1];
LocalDerivativeMatrix[4, 0] = LocalDerivativeMatrix[5, 3] = gradN[0, 2];
LocalDerivativeMatrix[6, 0] = LocalDerivativeMatrix[7, 3] = gradN[0, 3];
LocalDerivativeMatrix[1, 1] = LocalDerivativeMatrix[0, 2] = gradN[1, 0];
LocalDerivativeMatrix[3, 1] = LocalDerivativeMatrix[2, 2] = gradN[1, 1];
LocalDerivativeMatrix[5, 1] = LocalDerivativeMatrix[4, 2] = gradN[1, 2];
LocalDerivativeMatrix[7, 1] = LocalDerivativeMatrix[6, 2] = gradN[1, 3];
return(LocalDerivativeMatrix);
}
private Matrix LocalStiffnessMatrixFunction(double ksi, double eta)
{
Matrix derivativeMatrix = GetLocalDerivativeMatrix(elementCurrent, ksi, eta);
Jacobian J = new Jacobian();
J.Element = elementCurrent;
//Matrix VariableMatrixOnElement = GetVariableMatrixOnElement(elementCurrent, ksi, eta);
return(derivativeMatrix * ConstMatrix * Matrix.Transpose(derivativeMatrix) * J.GetJacobianDeterminant(ksi, eta));
}
private Matrix LocalVectorFunction(double ksi, double eta)
{
Matrix derivativeMatrix = GetLocalDerivativeMatrix(elementCurrent, ksi, eta);
Jacobian J = new Jacobian();
J.Element = elementCurrent;
Matrix VariableVectorOnElement = GetVariableVectorOnElement(elementCurrent, ksi, eta);
return(derivativeMatrix * VariableVectorOnElement * J.GetJacobianDeterminant(ksi, eta));
}
