/// <summary>
/// Integrates the shear force along intersection of element with defined plane.
/// </summary>
/// <param name="element">The element.</param>
/// <param name="plane">The plane.</param>
/// <returns>Integrated force</returns>
public static Force IntegrateNormalForce(this TriangleFlatShell element, Plane plane, LoadCombination cmb)
{
//step 1: does intersect?
//step 2: get a tensor (no matter where, this is constant stress)
//step 3: find rotation amount for tensors
//step 4: rotate tensors
//step 5: integrate forces
if (!DoesIntersects(element, plane))
return Force.Zero;
var intersection = GetIntersection(element, plane);
//step 2
var tensor = element.GetInternalForce(0, 0, cmb);
//step 3
var t = element.GetTransformationMatrix().Transpose(); //transpose of t
var nLocal = (Vector)(t * plane.Normal.ToMatrix()).ToPoint();//project of N to local element coord system
var theta = Math.Atan2(nLocal.Y, nLocal.X) - Math.PI / 2;
//step 4
var rotatedTensor = MembraneStressTensor.Rotate(tensor.MembraneTensor, theta);
// shear direction
var shearLocalDirection = new Vector(Math.Cos(theta), Math.Sin(theta), 0);//direction of shear force in local element coord system, which is vector I rotated by amount theta
var shearGlobalDirection = (Vector)(t.Transpose() * shearLocalDirection.ToMatrix()).ToPoint();
var fShearAmount = rotatedTensor.Txy * element.Thickness * intersection.Length;//shear force
var shearForce = fShearAmount * shearGlobalDirection.GetUnit();
return new Force(shearForce, Vector.Zero);
}
public static FlatShellStressTensor[] GeTensorsAtIntersection(this TriangleFlatShell element, Plane plane, int n)
{
var buf = new List<FlatShellStressTensor>();
var globalPoints = GetIntersectionPoints(element, plane, n);
if (!globalPoints.Any())
return buf.ToArray();
var t = element.GetTransformationMatrix().Transpose(); //transpose of t
var locals = globalPoints.Select(i => (t*i.ToMatrix()).ToPoint()).ToArray();
var lpts = element.GetLocalPoints();
var tensors =
locals.Select(i => element.GetInternalForce(i.X, i.Y, LoadCombination.DefaultLoadCombination)).ToArray();
return tensors;
}
