FloatMatrix Quadr::ComputeStiff()
{
FloatArray GaussCoor(2);
GaussPoint B;
FloatMatrix G(2, 2);
FloatMatrix BT(3, 2);
FloatMatrix DT(3, 3);
double W1,W2;
DMatrix = ComputeConstitutiveMatrix();
for (int inode = 0; inode < 4; inode++)
{
for (int jnode = 0; jnode < 4; jnode++)
{
for (int iksi = 0; iksi < 3; iksi++)
{
GaussCoor .at(0) = Gauss3[iksi];
W1 = Weight3[iksi];
for (int ieta = 0; ieta < 3; ieta++)
{
GaussCoor.at(1) = Gauss3[ieta];
W2 = Weight3[ieta];
B.Init(0, GaussCoor);
ComputeJacobi(B);
BMatrix = ComputeBMarix(inode);
BT=BMatrix.Trans();
//BT.Print();
DT = BT.Mult(DMatrix);
//DT.Print();
BMatrix = ComputeBMarix(jnode);
G = DT.Mult(BMatrix);
W2 = W1*W2*Det;
G = G.Mult(W2);
//G.Print();
Stiff.at(2 * inode, 2 * jnode) += G.at(0, 0);
Stiff.at(2 * inode + 1, 2 * jnode) += G.at(1, 0);
Stiff.at(2 * inode, 2 * jnode + 1) += G.at(0, 1);
Stiff.at(2 * inode + 1, 2 * jnode + 1) += G.at(1, 1);
}
}
}
}
//cout << "**********************************************" << endl;
//Stiff.Print();
return Stiff;
}
FloatArray Quadr::ComputeStress()
{
const double a = 1 + sqrt(3) / 2, b = -1.0 / 2, c = 1 - sqrt(3) / 2;
FloatMatrix TransMatrix(4, 4);
TransMatrix.at(0, 0) = a;
TransMatrix.at(0, 1) = b;
TransMatrix.at(0, 2) = c;
TransMatrix.at(0, 3) = b;
TransMatrix.at(1, 0) = b;
TransMatrix.at(1, 1) = a;
TransMatrix.at(1, 2) = b;
TransMatrix.at(1, 3) = c;
TransMatrix.at(2, 0) = c;
TransMatrix.at(2, 1) = b;
TransMatrix.at(2, 2) = a;
TransMatrix.at(2, 3) = b;
TransMatrix.at(3, 0) = b;
TransMatrix.at(3, 1) = c;
TransMatrix.at(3, 2) = b;
TransMatrix.at(3, 3) = a;
Strain.Clear();
GaussPoint B;
FloatArray Coor;
FloatArray TransTemp(4);
Coor.SetSize(2);
Coor.at(0) = 0;
Coor.at(1) = 0;
B.Init(0, Coor);
ComputeJacobi(B);
BMatrixBig = ComputeBMatrix();
//BMatrixBig.Print();
//Displacement.Print();
Strain = BMatrixBig.Mult(Displacement);
Stress = DMatrix.Mult(Strain);
for (int inode = 0; inode < 4; inode++)
{
Coor.at(0) = P4ksicor[inode];
Coor.at(1) = P4etacor[inode];
B.Init(0, Coor);
ComputeJacobi(B);
BMatrixBig = ComputeBMatrix();
GaussStrain[inode] = BMatrixBig.Mult(Displacement);
GaussStress[inode] = DMatrix.Mult(Strain);
//GaussStrain[inode].Print();
}
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 4; j++)
{
TransTemp.at(j) = GaussStrain[j].at(i);
}
TransTemp = TransMatrix.Mult(TransTemp);
for (int j = 0; j < 4; j++)
{
NodeStrain[j].at(i) = TransTemp.at(j);
}
for (int j = 0; j < 4; j++)
{
TransTemp.at(j) = GaussStress[j].at(i);
}
TransTemp = TransMatrix.Mult(TransTemp);
for (int j = 0; j < 4; j++)
{
NodeStress[j].at(i) = TransTemp.at(j);
}
}
return NULL;
}
