Vertical BarElements return NaN

[SerGlushko]

Describe the bug Greetings! First of all, thank you for your continued development and support of this fantastic library. I've been using BFE.NET version from autumn 2019 in my project and decided to migrate to the newest build. I have encountered an issue: any 2D frame or truss I create have NaN values of support reactions, internal forces and deformations for the vertical elements, e.g BarElement (0, 0, 0), (0, 0, 1). This issue might also effect FrameElement2Node elements.

To Reproduce This is the code We've used and caused wrong result/ runtime error

var m1 = new Model();

m1.Nodes.Add(new Node(0, 0, 0) { Label = "n1" });

m1.Nodes.Add(new Node(0, 0, 6) { Label = "n2" });

m1.Nodes["n1"].Constraints = new Constraint(dx: DofConstraint.Fixed, dy: DofConstraint.Fixed, dz: DofConstraint.Fixed, rx: DofConstraint.Fixed, ry: DofConstraint.Fixed, rz: DofConstraint.Fixed);

m1.Nodes["n2"].Loads.Add(new NodalLoad(new Force(0, 0, -4000, 0, 0, 0)));

m1.Elements.Add(new BarElement(m1.Nodes["n1"], m1.Nodes["n2"]) { Label = "r1" });

(m1.Elements["r1"] as BarElement).Behavior = BarElementBehaviours.FullFrame;

(m1.Elements["r1"] as BarElement).Section = new BriefFiniteElementNet.Sections.UniformParametric1DSection(16.43 / 10000, 541.22 / 100000000, 44.92 / 100000000, 541.22 / 100000000 + 44.92 / 100000000);

(m1.Elements["r1"] as BarElement).Material = BriefFiniteElementNet.Materials.UniformIsotropicMaterial.CreateFromYoungPoisson(210 * Math.Pow(10, 9), 0.3);

m1.Solve();

var r11 = m1.Nodes[0].GetSupportReaction();

var r12 = m1.Nodes[1].GetSupportReaction();

Console.WriteLine("n0 reaction: {0}", r11);

Console.WriteLine("n1 reaction: {0}", r12);

Console.ReadKey();

Expected behavior The expected result for n0 is "F: 0, 0, 4000, M: 0, 0, 0"

Additional context

I've tested multiple frame configurations and ones without strictly vertical elements had correct results.

[epsi1on]

I think there is problem with transformation calculations I'll check this week and fix the issue. Thanks

[epsi1on]

Hi This works fine now. this is the result of your code I did not changed the code.

[SerGlushko]

Hello, I've downloaded the latest version of the library, results remain the same for me

[epsi1on]

Could you please also check with model.Solve_MPC() instead of model.Solve()? I've coppied your code into this file: https://github.com/BriefFiniteElementNet/BriefFiniteElement.Net/blob/7ab78543b48b2f50fd1942dba29f686033e5dd3e/BriefFiniteElementNet.Validation/GithubIssues/Issue96.cs#L10

If you set BriefFiniteElementNet.TestConsole.csproj as startup project, it will call

https://github.com/BriefFiniteElementNet/BriefFiniteElement.Net/blob/7ab78543b48b2f50fd1942dba29f686033e5dd3e/BriefFiniteElementNet.TestConsole/Program.cs#L39

Could you please check?

[SerGlushko]

I've tested Solve_MPC method, it returns NaN. Same for the project in the TestConsole

Here's the matrix:

Click to expand

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[epsi1on]

There was problem with bar transformation which is fixed. Could you please do check again? Thanks

[SerGlushko]

The example works correctly now, but I've tried the latest version in my main project that uses some legacy code too. The issue is still there for FrameElement2Node elements

[epsi1on]

it should be fixed, could you please do check again?

[SerGlushko]

It works for FrameElement2Node now too. Thank you!