Analysis of the effect of stiffener on the buckling capacity and non-elastic behavior of bracing gusset plates

Due to the high rigidity and strength of bracings, they are widely employed in seismic design of steel buildings. Bracing plays a fundamental role in the absorption and dissipation of earthquake forces. Failures of braced steel buildings are often due to the shortage of compressive strength and out-of-plane buckling of bracing connections. One of the factors contributes to the buckling behavior of gusset plates is position and type of connection of bracing to the gusset plate. In this paper, the pre- and post-buckling behavior of gusset plates is studied considering the presence or absence of longitudinal and transverse stiffener on the bracing splice plates as well as the arrangement of edge stiffener on gusset plates. To this purpose, a nonlinear static analysis is performed, the results of which are compared to the results obtained from the laboratory model. Results of the research show that application of longitudinal stiffeners leads to an increase in the buckling and post-buckling behavior of gusset plate while transverse stiffeners only influence the post-buckling behavior of gusset plate. In addition, implementation of double stiffeners on a gusset plate somewhat adds to the buckling capacity of the gusset plate, but affects post-buckling behavior of gusset plate better.