/// <summary>
/// Gets the internal stress at defined location.
/// tensor is in local coordinate system.
/// </summary>
/// <param name="isoLocation">The location for the stress probe in iso coordinates. Order: x,y,z. Maximum bending stress at the shell thickness (z=1.0). Must be withing 0 and 1.</param>
/// <param name="combination">The load combination.</param>
/// <param name="probeLocation">The probe location for the stress.</param>
/// <returns>Stress tensor of flat shell, in local coordination system</returns>
/// <remarks>
/// For more info about local coordinate of flat shell see page [72 of 166] (page 81 of pdf) of "Development of Membrane, Plate and Flat Shell Elements in Java" thesis by Kaushalkumar Kansara freely available on the web
/// </remarks>
public CauchyStressTensor GetInternalStress(double[] isoLocation, LoadCase cse, SectionPoints probeLocation)
{
//added by rubsy92
if (isoLocation[2] < 0 || isoLocation[2] > 1.0)
{
throw new Exception("z must be between 0 and 1. 0 is the centre of the plate and 1 is on the plate surface. Use the section points to get the top/bottom.")
{
};
}
var helpers = GetHelpers();
var gst = new GeneralStressTensor();
var tr = this.GetTransformationManager();
var ld = this.Nodes.Select(i => tr.TransformGlobalToLocal(i.GetNodalDisplacement(cse))).ToArray();
for (var i = 0; i < helpers.Count(); i++)
{
var st = helpers[i].GetLocalInternalStressAt(this, ld, isoLocation);
gst += st;
}
var buf = new CauchyStressTensor();
buf += gst.MembraneTensor;
{
var lambda = 0.0;
switch (probeLocation)
{
case SectionPoints.Envelope:
{
var thickness = Section.GetThicknessAt(isoLocation);
//top
var bufTop = new CauchyStressTensor();
bufTop += gst.MembraneTensor;
bufTop += BendingStressTensor.ConvertBendingStressToCauchyTensor(gst.BendingTensor, thickness, 1.0);
//bottom
var bufBottom = new CauchyStressTensor();
bufBottom += gst.MembraneTensor;
bufBottom += BendingStressTensor.ConvertBendingStressToCauchyTensor(gst.BendingTensor, thickness, -1.0);
if (Math.Abs(CauchyStressTensor.GetVonMisesStress(bufTop)) > Math.Abs(CauchyStressTensor.GetVonMisesStress(bufBottom)))
{
buf = bufTop;
}
else
{
buf = bufBottom;
}
break;
}
case SectionPoints.Top:
{
lambda = 1.0;
var thickness = Section.GetThicknessAt(isoLocation);
buf += BendingStressTensor.ConvertBendingStressToCauchyTensor(gst.BendingTensor, thickness, lambda);
break;
}
case SectionPoints.Bottom:
{
lambda = -1.0;
var thickness = Section.GetThicknessAt(isoLocation);
buf += BendingStressTensor.ConvertBendingStressToCauchyTensor(gst.BendingTensor, thickness, lambda);
break;
}
default:
break;
}
}
return(buf);
}
/// <summary>
/// Gets the internal stress at defined <see cref="isoLocation"/>.
/// tensor is in local coordinate system.
/// </summary>
/// <param name="loadCase">the load case </param>
/// <param name="isoLocation"></param>
/// <returns>Stress tensor of flat shell, in local coordination system</returns>
/// <remarks>
/// for more info about local coordinate of flat shell see page [72 of 166] (page 81 of pdf) of "Development of Membrane, Plate and Flat Shell Elements in Java" thesis by Kaushalkumar Kansara freely available on the web
/// </remarks>
public CauchyStressTensor GetLocalInternalStress(LoadCase loadCase, params double[] isoLocation)
{
var helpers = GetHelpers();
var gst = new GeneralStressTensor();
var tr = this.GetTransformationManager();
var ld = this.Nodes.Select(i => tr.TransformGlobalToLocal(i.GetNodalDisplacement(loadCase))).ToArray();
for (var i = 0; i < helpers.Count(); i++)
{
var st = helpers[i].GetLocalInternalStressAt(this, ld, isoLocation);
gst += st;
}
var buf = new CauchyStressTensor();
buf += gst.MembraneTensor;
if (isoLocation.Length == 3)// local Z and bending tensor does affect on cauchy tensor, only on center of plate where lambda=0 bending tensor have no effect on cauchy
{
//step2: update Cauchy based on bending: bending tensor also affects the Cauchy tensor regarding how much distance between desired location and center of plate.
//old code: buf.UpdateTotalStress(_section.GetThicknessAt(new double[] { localX, localY }) * localZ, probeLocation);
var lambda = 0.0;
if (isoLocation.Length == 3)
{
lambda = isoLocation[2];
}
if (lambda > 1.0 || lambda < -1.0)
{
throw new Exception("lambda must be between -1 and +1")
{
}
}
;
var thickness = Section.GetThicknessAt(isoLocation);
var z = thickness * lambda;//distance from plate center, measure in [m]
buf -= BendingStressTensor.ConvertBendingStressToCauchyTensor(gst.BendingTensor, thickness, lambda);
/*epsi1on: no need to subtract, only need to add because negativeness of lambda taken into account in ConvertBendingStressToCauchyTensor
*
* if (lambda > 0)
* {
* //top -> add bending stress
* buf += gst.BendingTensor.ConvertBendingStressToCauchyTensor(thickness, lambda);
* }
* else
* {
* //bottom -> subtract bending stress
* buf -= gst.BendingTensor.ConvertBendingStressToCauchyTensor(thickness, lambda);
* }
*/
}
return(buf);
}
#endregion
}
/// <summary>
/// Gets the internal stress at defined location.
/// tensor is in local coordinate system.
/// </summary>
/// <param name="isoLocation">The location for the stress probe in iso coordinates. Order: x,y,z. Maximum bending stress at the shell thickness (z=1.0). Must be withing 0 and 1.</param>
/// <param name="combination">The load combination.</param>
/// <param name="probeLocation">The probe location for the stress.</param>
/// <returns>Stress tensor of flat shell, in local coordination system</returns>
/// <remarks>
/// for more info about local coordinate of flat shell see page [72 of 166] (page 81 of pdf) of "Development of Membrane, Plate and Flat Shell Elements in Java" thesis by Kaushalkumar Kansara freely available on the web
/// </remarks>
public CauchyStressTensor GetInternalStress(double[] isoLocation, LoadCombination combination, SectionPoints probeLocation)
{
var helpers = GetHelpers();
var gst = new GeneralStressTensor();
var tr = this.GetTransformationManager();
var ld = this.Nodes.Select(i => tr.TransformGlobalToLocal(i.GetNodalDisplacement(combination))).ToArray();
for (var i = 0; i < helpers.Count(); i++)
{
var st = helpers[i].GetLocalInternalStressAt(this, ld, isoLocation);
gst += st;
}
var buf = new CauchyStressTensor();
buf += gst.MembraneTensor;
{
var lambda = 0.0;
switch (probeLocation)
{
case SectionPoints.Envelope:
{
var thickness = Section.GetThicknessAt(isoLocation);
//top
var bufTop = new CauchyStressTensor();
bufTop += gst.MembraneTensor;
bufTop += BendingStressTensor.ConvertBendingStressToCauchyTensor(gst.BendingTensor, thickness, 1.0);
//bottom
var bufBottom = new CauchyStressTensor();
bufBottom += gst.MembraneTensor;
bufBottom += BendingStressTensor.ConvertBendingStressToCauchyTensor(gst.BendingTensor, thickness, -1.0);
if (Math.Abs(CauchyStressTensor.GetVonMisesStress(bufTop)) > Math.Abs(CauchyStressTensor.GetVonMisesStress(bufBottom)))
{
buf = bufTop;
}
else
{
buf = bufBottom;
}
break;
}
case SectionPoints.Top:
{
lambda = 1.0;
var thickness = Section.GetThicknessAt(isoLocation);
buf += BendingStressTensor.ConvertBendingStressToCauchyTensor(gst.BendingTensor, thickness, lambda);
break;
}
case SectionPoints.Bottom:
{
lambda = -1.0;
var thickness = Section.GetThicknessAt(isoLocation);
buf += BendingStressTensor.ConvertBendingStressToCauchyTensor(gst.BendingTensor, thickness, lambda);
break;
}
default:
break;
}
}
return(buf);
}