public static void TestEndReleaseStyiffness()
{
//A NUMERICAL PROCEDURE FOR THE NONLINEAR ANALYSIS OF REINFORCED CONCRETE FRAMES WITH INFILL WALLS
//by MURAT EFE GÜNEY
//p. 51: 2.3 Condensation and Constraint Equations
var elm = new BarElement(2);
elm.Nodes[0] = new Node(-1, 0, 0);
elm.Nodes[1] = new Node(0, 0, 0);
//elm.Nodes[2] = new Node(1, 0, 0);
//elm.StartReleaseCondition = Constraints.FixedRX;
elm.Section = new UniformParametric1DSection(1, 2, 3, 4);
elm.Material = new UniformIsotropicMaterial(1, 0.3);
var newConds = new Constraint[elm.NodeCount];
{
for (int i = 0; i < newConds.Length; i++)
{
newConds[i] = Constraints.Fixed;
}
newConds[0].DZ = DofConstraint.Released;
}
Array.Copy(newConds, elm._nodalReleaseConditions, newConds.Length);
var kr2 = elm.GetLocalStifnessMatrix();
for (var i = 0; i < elm.NodeCount; i++)
{
elm.NodalReleaseConditions[i] = Constraint.Fixed;
}
var kfull = elm.GetLocalStifnessMatrix();
var kr = GetCondensedStiffness(kfull, newConds);
var ratio = Matrix.DotDivide(kr, kr2);
ratio.Replace(double.NaN, 0);
var d = (kr - kr2);
var dmax = d.Max(i => Math.Abs(i));
}
private static void TestBar()
{
var iy = 0.03;
var iz = 0.02;
var a = 0.01;
var j = iy + iz;
var e = 7;
var g = 11;
var rho = 13;
var model = new Model();
model.Nodes.Add(new Node(0, 0, 0));
model.Nodes.Add(new Node(1, 0, 0));
var barElement = new BarElement(model.Nodes[0], model.Nodes[1]);
barElement.Behavior = BarElementBehaviours.FullFrame;
var frameElement = new FrameElement2Node(model.Nodes[0], model.Nodes[1])
{
Iy = iy,
Iz = iz,
A = a,
J = j,
E = e,
G = g,
MassDensity = rho
};
//barElement.Material = new UniformBarMaterial(e, g, rho);
barElement.Section = new UniformParametric1DSection()
{
Iy = iy, Iz = iz, A = a
};
frameElement.MassFormulationType = MassFormulation.Consistent;
//barElement.EndConnection = BarElementEndConnection.TotallyHinged;
//barElement.StartConnection = BarElementEndConnection.TotallyHinged;
frameElement.HingedAtStart = true;
//frameElement.HingedAtEnd = true;
var frameM = frameElement.GetLocalStiffnessMatrix();
//MathUtil.FillLowerTriangleFromUpperTriangle(frameM);
var barM = barElement.GetLocalStifnessMatrix();
var t = 1; //- 1e-10;
var d = (frameM - t * barM); //
var dMax = d.CoreArray.Max(i => Math.Abs(i));
model.Nodes[0].Constraints = Constraint.Fixed;
model.Solve();
}
