Ultimate strength of tube–gusset plate connections considering eccentricity

A numerical analysis and experimental study were performed to investigate the behavior and strength of tube–gusset connections subjected to axial and axial brace force. To investigate the behavior of the connections, experiments were conducted by applying three directional loads. Local buckling and local plastic bending deformation of the connection were observed from the test. Analytical results were compared with test results for the limited cases. Of primary interests here is the eccentricity which may increase the strength of the connection. To suggest a formula for the strength of tube–gusset connections, axial brace forces are replaced by equivalent wall moment and eccentric vertical component force of axial brace force. Ultimate strength formula for each of the forces were proposed. Finally, nondimensionalized ultimate strength interaction relationships between the wall moment of tube (Mw), vertical axial force (Pv), and eccentric vertical component force of axial brace force (Pe) were formulated through parametric study.