fealite / fealite2d

A finite element analysis library for 2D frame, beams and truss elements using C#

FEALiTE2D

A fast and reliable finite element analysis library for 2D frame, beam and truss elements using C#.

	FEALiTE2D
	FEALiTE2D.Plotting

Features

• Analysis of frame, beam, truss/link members.
• Various load types:
  • Frame point load.
  • Frame uniform load.
  • Frame trapezoidal load.
  • Nodal point load.
  • Support displacement.
• Loads can be set in global and element's local coordinate system.
• Nodes can have local and global coordinate system.
• Loads can be assigned in variant load cases of different natures.
• Loads can be combined in a load combination with load magnification factors.
• Rigid Supports of 3 degrees of freedom.
• Elastic supports using translational and rotational springs.
• Variety of predefined cross-sections.
• Linear mesher for better analysis results.

Sign convention for loads in global and local coordinate system.

Example

Here is a 2D framed strcture subjected to various loading conditions

public void TestStructure()
{
     // units are kN, m
     FEALiTE2D.Structure.Structure structure = new FEALiTE2D.Structure.Structure();

     Node2D n1 = new Node2D(0, 0, "n1");
     Node2D n2 = new Node2D(9, 0, "n2");
     Node2D n3 = new Node2D(0, 6, "n3");
     Node2D n4 = new Node2D(9, 6, "n4");
     Node2D n5 = new Node2D(0, 12, "n5");
     n1.Restrain(NodalDegreeOfFreedom.UX, NodalDegreeOfFreedom.UY, NodalDegreeOfFreedom.RZ); //fully restrained
     n2.Restrain(NodalDegreeOfFreedom.UX, NodalDegreeOfFreedom.UY, NodalDegreeOfFreedom.RZ); //fully restrained

     structure.AddNode(n1, n2, n3, n4, n5);
     IMaterial material = new GenericIsotropicMaterial() { E = 30E6, U = 0.2, Label = "Steel", Alpha = 0.000012, Gama = 39885, MaterialType = MaterialType.Steel };
     IFrame2DSection section = new Generic2DSection(0.075, 0.075, 0.075, 0.000480, 0.000480, 0.000480 * 2, 0.1, 0.1, material);
    
     FrameElement2D e1 = new FrameElement2D(n1, n3, "e1") { CrossSection = section };
     FrameElement2D e2 = new FrameElement2D(n2, n4, "e2") { CrossSection = section };
     FrameElement2D e3 = new FrameElement2D(n3, n5, "e3") { CrossSection = section };
     FrameElement2D e4 = new FrameElement2D(n3, n4, "e4") { CrossSection = section };
     FrameElement2D e5 = new FrameElement2D(n4, n5, "e5") { CrossSection = section };
     structure.AddElement(new[] { e1, e2, e3, e4, e5 });

     LoadCase loadCase = new LoadCase("live", LoadCaseType.Live);
     structure.LoadCasesToRun.Add(loadCase);
     n2.SupportDisplacementLoad.Add(new SupportDisplacementLoad(10E-3, -5E-3, -2.5 * Math.PI / 180, loadCase));
     e3.Loads.Add(new FramePointLoad(0, 0, 7.5, e3.Length / 2, LoadDirection.Global, loadCase));
     e4.Loads.Add(new FrameTrapezoidalLoad(0, 0, -15, -7, LoadDirection.Global, loadCase, 0.9, 2.7));
     e5.Loads.Add(new FrameUniformLoad(0, -12, LoadDirection.Local, loadCase));
     n3.NodalLoads.Add(new NodalLoad(80, 0, 0, LoadDirection.Global, loadCase));
     n5.NodalLoads.Add(new NodalLoad(40, 0, 0, LoadDirection.Global, loadCase));
     n1.NodalLoads.Add(new NodalLoad(40, 0, 0, LoadDirection.Global, loadCase));

     structure.LinearMesher.NumberSegements = 35;
     structure.Solve();
}

Ploting internal forces and displacments

Use ploting Library FEALiTE2D.Plotting, create dxf plotter with correct options and save the file on your local machine.

var op = new FEALiTE2D.Plotting.Dxf.PlottingOption 
{ 
    NFDScaleFactor = 0.01,
    SFDScaleFactor = 0.01,
    BMDScaleFactor = 0.01, 
    DisplacmentScaleFactor = 1,
    DiagramsHorizontalOffsets = 10 
};
var plotter = new FEALiTE2D.Plotting.Dxf.Plotter(structure, op);
plotter.Plot("D:\\internal forces.dxf", loadCase);

fealite2d's Issues

NRE

FEALiTE2D/FEALiTE2D/Structure/PostProcessor.cs

Line 302 in db1aaba

FrameUniformLoad uniformLoad = uL.GetLoadValueAt(element, x) as FrameUniformLoad;

This will always be null if L2 was set.

Please share an example to show how a truss with flexible joints is computed.

It's like all the joints of beam members in this program are rigid joints.