BeamColumeJoint and Joint2D modelling

[Brave Chen]

Dear stko operation team, good afternoon. I'm a beginner of stko. I've been writing TCL files before. Now it's very convenient to use stko. I now have several problems:
About the use of beamcolumejoint and joint2d units, I don't know how to assign them to the model. I've tried to assign them to the four points shown in the figure or to the center point, but they are not correct.
In addition, my joint2d unit cannot select the material of MatC. What's the matter?
Finally, I read about rcjoint3d in other posts on the forum. I didn't find this node on the OPENSEES official website. Is this a node made by stko? Is it different from beamcolumejoint and joint2d? What I do is a plane structure. Can I also use rcjoint3d?
I sent my model to you together. I assigned the beamcolumejoint node to the center point，but it doesn't seem right. If it is convenient for you, can you help me add the beamcolumejoint node correctly？
This problem bothers me very much. I sincerely hope for your help. I wish you a happy life!

joint2D.jpg (145.93 KiB) Viewed 2466 times

beamcolumejoint.jpg (102.26 KiB) Viewed 2466 times

RC -beam-colume joint.zip

(149.06 KiB) Downloaded 176 times

[STKO Team]

In addition, my joint2d unit cannot select the material of MatC. What's the matter?

We have a bug there! thanks, we just solved it and it will be available in the next STKO release

About the use of beamcolumejoint and joint2d units, I don't know how to assign them to the model. I've tried to assign them to the four points shown in the figure or to the center point, but they are not correct.

For the joint2D, since it requires 5 nodes, you need to use a Generic Interaction, paying attention at the order of the vertices you select.
For the beamColumnJoint, it requires 4 nodes, so you can simply create a 4-node face (see the attached file) and "Merge" it with the beams and columns.
Finally, in the mesh settings for faces, make sure to use Quadrilateral Structured Mesh.

Finally, I read about rcjoint3d in other posts on the forum. I didn't find this node on the OPENSEES official website. Is this a node made by stko? Is it different from beamcolumejoint and joint2d? What I do is a plane structure. Can I also use rcjoint3d?

It is an STKO automation that used the scissor model. It is not in OpenSees, but it is an assembly of components that are in OpenSees, such as zeroLength and rigid links. It can be used only in 3D.

This problem bothers me very much. I sincerely hope for your help. I wish you a happy life!

Here is your model.
I changed the geometry to make it work. I also changed some settings in the analysis to improve convergence.
However, double-check your material parameters and/or boundary conditions, as the load multiplier of the displacement-controlled analysis is very low for -5mm displacement

RC -beam-colume joint.zip

(154.86 KiB) Downloaded 166 times

[Brave Chen]

Dear STKO team
Thank you very much for your patience, but I still have some problems. "Invalid number of node" appears when I run after setting. I think it is caused by redundant points. I carefully compared the model you sent me. I found that even after merging, I have two points at this position in the figure, and the problem should appear here.
In addition, is there any order requirement when creating four point faces? When assigning beamcolumejoint material, is there any order requirement when selecting the face composed of these four points? I think there should be. Otherwise, how does STKO know which material is for which point.
I will send you my model again. I hope you can help me modify it, and I sincerely hope you can answer my above questions, Thank you very much！

微信截图_20220406215900.png (67.87 KiB) Viewed 2419 times

[STKO Team]

Here is the working file:

RC-beamcolumJoint.zip

(178.29 KiB) Downloaded 166 times

but I still have some problems. "Invalid number of node" appears when I run after setting

This is due to the wrong mesh type: you are using a triangular mesh, while the element needs a quadrilateral mesh (4 nodes).

I think it is caused by redundant points. I carefully compared the model you sent me. I found that even after merging, I have two points at this position in the figure, and the problem should appear here.

The redundant points are not the source of the above-mentioned error but will cause problems later on, as in this case the joint will be detached from the beams... It happened because you used several nested compounds instead of a "Merge" command.

Here is what I did to fix your model:

• "Explode" (Explode command) your compound multiple times (because you created nested compounds) until you see simple geometries in the work tree

  

  rcj_explode.png (41.49 KiB) Viewed 2414 times

• Merge those geometries with the Merge command (not the compound!). You will see that you will correctly have just 1 vertex there...

  

  rcj_merge.png (10.54 KiB) Viewed 2414 times

• Your mesh is wrong because you used triangular elements instead of quadrilateral, but also because you subdivided into 3 subdivisions the joint face (while it should be only 1 face per joint)

  

  rcj_wrong_mesh.png (12.55 KiB) Viewed 2414 times

• Choose a quadrilateral mesh for joint panels with the Mesh Settings command and press Ok -> Done

  

  rcj_quad_mesh.png (67.93 KiB) Viewed 2414 times

• Use the Edge Seed command to imposed a different seed to the sides of the joint panel. You need just 1 subdivision here:

  

  rcj_1_subdiv_quad.png (79.1 KiB) Viewed 2414 times

• Finally, regarding the node numbering, you have to create the quad following the same numbering required by the opensees element. You already did it correctly:

  

  rcj_good_numbering.png (83.5 KiB) Viewed 2414 times

[Brave Chen]

Great, my problem has been completely solved. Thank you for your patient guidance and wish you success in your work and happiness every day

[STKO Team]

You're welcome