Strength capacity of the gusset plate connection with fillet welds

Braced frames are commonly used as lateral-load resisting systems in seismic design. The braces are connected to the beams and columns by gusset plate connections. The fracture of the interface fillet welds between the gusset plate and the beam and column is one of the most undesirable failure modes in the design of the gusset plate connection. To improve the understanding and design of the interface weld of the gusset plate connection, a series of parametric study was undertaken using a verified finite element model. The axial brace force mainly transferred by the interface weld within an effective region of the gusset plate connection. In addition, the effective length of the interface weld was affected by the gusset plate size, brace angle, and eccentricity of brace. According to the parametric study results, one of the current design methods in Japan was recommended.