EXPERIMENTAL STUDY ON SEISMIC BEHAVIOR OF FRAME JOINTS WITH CONCRETE-FILLED STEEL TUBULAR COLUMN AND DOUBLE-SIDED COMPOSITE BEAM

In order to study the seismic performance of frame joints with concrete-filled steel tubular column and double-sided composite beam, three cross-shaped frame joints of a double composite steel-concrete beam and one cross-shaped frame joint of a normal single composite steel-concrete beam were designed, and low-cycle reciprocating loading tests were carried out to compare and analyze their failure modes and ultimate bearing capacity, initial stiffness, energy dissipation capacity, ductility, stiffness degradation, and other seismic performance indicators. By changing the thickness and load transfer mode of the bottom concrete slab, the influence of different thickness and different load transfer mode of the bottom concrete slab on the mechanical properties of the double-sided composite beam is studied. The results show that: compared with normal single composite steel-concrete beam-frame joints, double composite steel-concrete beam-frame joints have higher bearing capacity and stiffness, and are suitable for structures with larger loads, but have no obvious advantages in ductility, stiffness degradation and energy dissipation capacity. There is no obvious difference in the effect of concentrated and uniform load transfer on the seismic performance of double composite beams, and prefabricated concrete slabs and bolted connections are more convenient and reliable.