I am trying to simulate the above truss in Abaqus to get its natural frequencies through Modal Analysis. The joints are connected through welding. However, I am unsure how to define the interaction and constraints to simulate the welded connection between the joints of the truss in Abaqus. I have attached some images as a reference and I have the results of Abaqus as well. The boundary condition is pin-pin.

How can I be sure about the constraint that I defined?

I defined 5 constraints in the joint plus two boundary conditions.

The version of my Abaqus is 2020.