| This topic proposes a new RCS composite frame structure that is high strength concrete columns confined by butt-welded closed compound stirrups and honeycombed steel beam combinational frame structure.In order to promote the popularization and application of the composite structure, it is necessary to study the seismic behavior and deformation characteristics of the beam-column assemblies of composite structure.In order to study the Seismic behavior and deformation characteristics of the Beam-Column Sub-assemblies of a new type of composite structure, this paper change the steel beam section as a parameter, and the low frequency cyclic loading tests of 6 Beam-Column Sub-assemblies which the scale is 1/2 had been taken on. The test phenomena and failure mode were described. According to the test results analysis, the important aspects of affect seismic behavior and deformation characteristics of the beam-column joints comprehensively. The aspects include the strain changes, hysteretic curve, skeleton curve, stiffness degradation, displacement ductility, energy dissipation capacity etc. Test results indicate that:(1) With decrease of the failure mode of specimens is converted from flexural failure of steel beams into shear failure of joint core. According to the analysis, this paper argues that 1/250, 1/75, 1/45, 1/25 can be used as the reference value of displacement angle which is based on seismic design in the normal use, temporary use, life safety and close to the collapse of the four stages.(2) Since set steel hoop in the the steel-concrete beam column joints had been used, the concrete in the joints is in 3D Compression state, and shear capacity of the new RCS compound joints increases. Shear deformation of the new RCS compound joints is smaller than normal joint. It achieves the design requirements for seismic design specifications "strong joint and weak members".(3) High-strength bolts embedded in the steel-concrete beam column joints can be helpful for steel beam concrete column assembly connector, and is conducive to the replacement when earthquake damaged steel beams. Due to the pre-load applied by high-strength bolts on beam plate and steel hoop in the steel-concrete beam column, steel beam and joints is tighted when it is forced and the connection angle is small. Test results indicate that this form of connection can transmitted moment reliably and show a good connection performance.(4) Deformation component due to the beam flexual caused a large proportion approximately 60% in the story displacement when the shear deformation of the new RCS compound joints is small which approximate 10%.(5) Basised on the experimental study,restoring force models of the beam-column sub-assemblies in diffrent sections steel beam of a new type of composite structure are proposed.The skeleton curves of the proposed restoring force model were already indicated well with the test which verified the exactness of proposal restoring fore model.This provided some reference for elastic-plastic seismic response analysis of the Beam-Column Sub-assemblies of a new type of composite structure. |
PDF Full Text Request