public double GetTensionFlangeRuptureStrength(ISectionI ShapeIGross, ISectionI ShapeINet)
{
double phiM_n = -1;
double F_y = Section.Material.YieldStress;
double F_u = Section.Material.UltimateStress;
double S_g = Math.Min(ShapeIGross.S_xBot, ShapeIGross.S_xTop);
SectionIWithFlangeHoles netSec = ShapeINet as SectionIWithFlangeHoles;
if (netSec == null)
{
throw new Exception("Net section shape not recognized");
}
double A_fgB = ShapeIGross.b_fBot * ShapeIGross.t_fBot;
double A_fgT = ShapeIGross.b_fTop * ShapeIGross.t_fTop;
double A_fnB = netSec.b_fBot * netSec.t_fBot - netSec.b_hole * netSec.N_holes;
double A_fnT = netSec.b_fTop * netSec.t_fTop - netSec.b_hole * netSec.N_holes;
double Y_t = GetY_t();
double BotFlangeRuptureMoment = GetNetSectionRuptureStrength(A_fnB, A_fgB, Y_t);
double TopFlangeRuptureMoment = GetNetSectionRuptureStrength(A_fnT, A_fgT, Y_t);
phiM_n = Math.Min(BotFlangeRuptureMoment, TopFlangeRuptureMoment);
return(phiM_n);
}
public void SectionIWithFlangeHolesRolledReturnsIy()
{
SectionIWithFlangeHoles shape = new SectionIWithFlangeHoles("", 17.7, 6.0, 0.425, 0.3, 0.001, 2);
double Iy = shape.I_y;
double refValue = 15.3;
double actualTolerance = EvaluateActualTolerance(Iy, refValue);
Assert.LessOrEqual(actualTolerance, tolerance);
}
public double GetFlexuralStrength(double L_b)
{
double phiM_n = 0.0;
double F_y = this.Section.Material.YieldStress;
double F_u = this.Section.Material.UltimateStress;
ISection section = Section.Shape;
bool IsValidGrossSection = ValidateGrossSection();
bool IsValidNetSection = true;
if (this.NetSectionShape != null)
{
IsValidNetSection = ValidateNetSection();
}
double phiM_nLTB, phiM_nNet, phiM_nGross;
//Gross Section Yielding
if (IsCompactDoublySymmetricForFlexure == true)
{
double Z = GrossSectionShape.Z_x;
phiM_nGross = 0.9 * F_y * Z;
}
else
{
double S = Math.Min(GrossSectionShape.S_xBot, GrossSectionShape.S_xTop);
phiM_nGross = 0.9 * F_y * S;
}
//Net Section Fracture
if (NetSectionShape == null)
{
phiM_nNet = double.PositiveInfinity;
}
else
{
if (GrossSectionShape is ISectionI)
{
if (NetSectionShape is ISectionI)
{
SectionIWithFlangeHoles netSec = NetSectionShape as SectionIWithFlangeHoles;
phiM_nNet = GetTensionFlangeRuptureStrength(GrossSectionShape as ISectionI, NetSectionShape as ISectionI);
}
else
{
throw new Exception("If I-Shape is used for Gross section,specify I-Shape with holes object type for net sections.");
}
}
else
{
phiM_nNet = 0.75 * NetSectionShape.Z_x * F_u;
}
}
//Lateral Stability
if (L_b != 0)
{
double S = NetSectionShape == null?Math.Min(GrossSectionShape.S_xBot, GrossSectionShape.S_xTop) : Math.Min(NetSectionShape.S_xBot, NetSectionShape.S_xTop);
double lambda = this.GetLambda(L_b);
double Q = this.GetBucklingReductionCoefficientQ(lambda);
double F_cr = F_y * Q;
phiM_nLTB = 0.9 * S * F_cr;
}
else
{
phiM_nLTB = double.PositiveInfinity;
}
List <double> LimitStates = new List <double>()
{
phiM_nLTB, phiM_nNet, phiM_nGross
};
phiM_n = LimitStates.Min();
return(phiM_n);
}
