The outer tube pair is described in the release definition by the M-N interaction diagram.
The bending resistance of the inner tube stub is defined by the M-φ diagram.
The axial load-bearing capacity of the connection depends on the interaction diagram of the outer tubes and determined by the N-ux diagram.
If the moment load of the connection rests...
~ within the interaction curve in the normal force interval described, the outer tubes transfer the bending moment and the connection reacts rigidly,
~ above the interaction curve in the normal force interval described, the outer tubes transfer the moment part dependent on the normal force, and with regard to the diagram, the stub transfers the rest until the yield moment is reached,
~ next to the interaction curve outside the normal force interval described, the outer tubes absorb the moment-dependent normal force and transition to a yielding process.