public double[,] CreateMassMatrix()
{
double[,] M = new double[16, 16];
double Mtot = new double();
//double scalar = 28.24;
//double[,] M = MatrixOperations.CreateDiagonalMatrix(8, scalar);
double[,] consinstentMass = new double[16, 16];
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
double[] gP = GaussPoints(i, j).Item1;
double[] gW = GaussPoints(i, j).Item2;
Dictionary <string, double[]> localdN = CalculateShapeFunctionsLocalDerivatives(gP);
double[,] J = CalculateJacobian(localdN);
double detJ = CalculateInverseJacobian(J).Item2;
double[,] Nmatrix = CalculateShapeFunctionMatrix(gP[0], gP[1]);
consinstentMass = MatrixOperations.MatrixAddition(consinstentMass, MatrixOperations.ScalarMatrixProductNew(Properties.Density * Properties.Thickness * detJ * gW[0] * gW[1],
MatrixOperations.MatrixProduct(MatrixOperations.Transpose(Nmatrix), Nmatrix)));
Mtot += Properties.Density * Properties.Thickness * detJ * gW[0] * gW[1];
}
}
double c = Mtot / MatrixOperations.Trace(consinstentMass);
//M = consinstentMass;
for (int i = 0; i <= 15; i++)
{
M[i, i] = c * consinstentMass[i, i];
}
//for (int i = 0; i <= 15; i++)
//{
// for (int j = 0; j <= 15; j++)
// {
// M[i, i] += Math.Abs(consinstentMass[i, j]);
// }
//}
//-------------------------------------------------------------------
//double[,] tempM = MatrixOperations.CreateDiagonalMatrix(8, 1.0);
//double length = 0.3;
//double scalar = Properties.Density * Properties.Thickness * length * (length / 3.0) / 4.0;
//double[,] M = MatrixOperations.ScalarMatrixProductNew(scalar, tempM);
//double waveSpeed = Math.Sqrt(Properties.YoungMod / Properties.Density);
//double deltatCritical = length * Math.Sqrt(1.0 - 0.33) / waveSpeed;
//--------------------------------------------------------------
//for (int i = 0; i < 2; i++)
//{
// for (int j = 0; j < 2; j++)
// {
// double[] gP = GaussPoints(i, j).Item1;
// double[] gW = GaussPoints(i, j).Item2;
// Dictionary<string, double[]> localdN = CalculateShapeFunctionsLocalDerivatives(gP);
// double[,] J = CalculateJacobian(localdN);
// double[,] invJ = CalculateInverseJacobian(J).Item1;
// double detJ = CalculateInverseJacobian(J).Item2;
// double[,] Nmatrix = CalculateShapeFunctionMatrix(gP[i], gP[j]);
// M = MatrixOperations.MatrixAddition(M, MatrixOperations.ScalarMatrixProductNew(Properties.Density * Properties.Thickness * detJ * gW[i] * gW[j],
// MatrixOperations.MatrixProduct(MatrixOperations.Transpose(Nmatrix), Nmatrix)));
// }
//}
//--------------------------------------------------------
//for (int i = 0; i < 8; i++)
//{
// M[i, i] = 4.0;
//}
//for (int i = 0; i < 6; i++)
//{
// M[i, i + 2] = 2.0;
// M[i + 2, i] = 2.0;
//}
//for (int i = 0; i < 4; i++)
//{
// M[i, i + 4] = 1.0;
// M[i + 4, i] = 1.0;
//}
//for (int i = 0; i < 2; i++)
//{
// M[i, i + 6] = 2.0;
// M[i + 6, i] = 2.0;
//}
//M = MatrixOperations.ScalarMatrixProductNew(0.67 * 0.8 * Properties.Density * Properties.Thickness / 32, M);
//MatrixOperations.PrintMatrix(M);
return(M);
}