Composite slab effects on self-centering connections with steel beams post-tensioned to a CFT column

Abstract

Four two-sided moment connections with steel beams post-tensioned to a concrete filled tubular (CFT) column were tested to investigate the effectiveness of using Reduced Flange Plates (RFPs) for energy dissipation. A composite slab was included in one alternate specimen to study the effects of a composite slab on self-centering cyclic behavior.Test results and correlation studies of a test specimen using a general-purpose nonlinear finite element analysis program ABAQUS (2003) showed that energy dissipation of the connection was substantially improved with the inclusion of the buckling-restrained RFPs. Connection strengths in positive moment were similar but in negative moment were increased on the order of 46 percent compared to the bare steel specimen so that the self-centering capability of the composite specimen was not observed during test. The composite slab, however, prevented beam's top flange from local buckling and reduced loss of the initial post-tensioning force at large inter story drifts.