Composite Beam-Column Connections

[sirwan]

Hi
Please help
1-I am modeling an RCS frame (composite frames with RC Columns and Steel beams) with composite Beam-Columns joints where steel beams passes directly through the reinforced concrete in joint location.I guess, I should use joint2D element where there should be two springs connected in series to account for joint deformations (both panel shear deformation and vertical bearing deformation, which are two joint failure modes characteristic to this type of composite connections ). The central spring which accommodates for panel shear deformation is constructed based on the uniaxial steel02 material and and the other springs that accounts for vertical bearing deformation are constructed based on a Tri-Linear Hysteretic material, however I am new to OpenSees, and I don't know using this set of springs connected in series will modify the frame actual stiffness or not? and if it does, how to recover frame original stiffness? Any guides would be so appreciated!...

2- Is there any other Joint model that can capture the behavior of these type of joints more realistic but rather still holds on a simplified model ?...

[fmk]

1) the best way to learn something is to try it out. build a small model with and without the joints and then do an eigenvalue analysis for both. this will give you an idea of what is happening with the frame stiffness. this should not take you more than an hour to do if you keep the model simple enough (never start out with large models ntil you understand the elements and materials you are using in a small model and are sure that they will capture the behaviour you are loooking for

2) we don't have many joint elements (your only choice is the Joint2D and BeamColumn joint) .. you could of course come up with your own joint model for each joint and put it inside a procedure so you could use it for every joint!

[sirwan]

Thanks for your guides, and all your helpful tips mentioned in your video tutorials , I really appreciate all your appreciable effort toward engineering community…
I will try it out, If there was any useful come out I will share…