void
SimpleCrossSection :: give3dBeamStiffMtrx(FloatMatrix &answer, MatResponseMode rMode, GaussPoint *gp, TimeStep *tStep)
{
StructuralMaterial *mat = dynamic_cast< StructuralMaterial * >( this->giveMaterial(gp) );
FloatMatrix mat3d;
double area, E, G, Iy, Iz, Ik;
double shearAreay, shearAreaz;
mat->give1dStressStiffMtrx(mat3d, rMode, gp, tStep);
E = mat3d.at(1, 1);
G = mat->give('G', gp);
area = this->give(CS_Area, gp);
Iy = this->give(CS_InertiaMomentY, gp);
Iz = this->give(CS_InertiaMomentZ, gp);
Ik = this->give(CS_TorsionMomentX, gp);
//shearCoeff = this->give(CS_BeamShearCoeff);
shearAreay = this->give(CS_ShearAreaY, gp);
shearAreaz = this->give(CS_ShearAreaZ, gp);
answer.resize(6, 6);
answer.zero();
answer.at(1, 1) = E * area;
///@todo Do this by using the general 3d tangent matrix instead somehow!!!
answer.at(2, 2) = shearAreay * G;
answer.at(3, 3) = shearAreaz * G;
//answer.at(2, 2) = shearCoeff * G * area;
//answer.at(3, 3) = shearCoeff * G * area;
answer.at(4, 4) = G * Ik;
answer.at(5, 5) = E * Iy;
answer.at(6, 6) = E * Iz;
}
void
SimpleCrossSection :: give2dBeamStiffMtrx(FloatMatrix &answer, MatResponseMode rMode, GaussPoint *gp, TimeStep *tStep)
{
StructuralMaterial *mat = dynamic_cast< StructuralMaterial * >( this->giveMaterial(gp) );
FloatMatrix mat3d;
double area, Iy, shearAreaz;
mat->give1dStressStiffMtrx(mat3d, rMode, gp, tStep);
area = this->give(CS_Area, gp);
Iy = this->give(CS_InertiaMomentY, gp);
shearAreaz = this->give(CS_ShearAreaZ, gp);
answer.resize(3, 3);
answer.zero();
answer.at(1, 1) = mat3d.at(1, 1) * area;
answer.at(2, 2) = mat3d.at(1, 1) * Iy;
answer.at(3, 3) = shearAreaz * mat->give('G', gp);
}