EXPERIMENT ON CYCLIC BEHAVIOR OF WELDED FLANGE PLATE REINFORCED CONNECTIONS OF STEEL MOMENT-RESISTING FRAMES

摘要

Welded flange plate (WFP) reinforced steel moment resisting-frame (MRF) connection is one of reinforced forms to improve its seismic performance, which may increase the plastic rotation of the connection and move the plastic hinge away from the adjacent place of beam and column interface. In order to investigate its hysteretic behavior, four half-scale specimens were tested under cyclic loads in this study. In the test, the effective of width-to-thickness ratios of beam flange and web and the attribution of panel zone on the performance of connections were taken into account. Test results revealed that all the specimens had good cyclic performance without brittle failure, and the plastic hinge was formed in the beam outside of the reinforced zone. The plastic rotation angles ranged from O.044rad to 0.054tad, in excess of the required 0.03tad for special moment resistingframe (SMRF) by FEMA 350. For all specimens, no local buckling occurred in the reinforced plates.So this reinforced type can be used in high seismic region. The following conclusion may be suggested through the test results: (l) When the design satisfied the demand of present Code for Seismic Design of Buildings, the influence of width-to-thickness ratio of beam flange on resistance and plastic deformation capacity of connection was less, though beam flange was more susceptible to buckling locally with the increase of the ratio; (2) With the increase of the height-to-thickness ratio of beam web, the influence on bearing capacity was larger; (3) For weaker panel zone, the bearing capacity decreased obviously, but the deformation capacity increased remarkably.