Research On Seismic Performance And Seismic Control Of Steel Beam-column Joint In Chinese Antique Style Buildings

Steel structure in Chinese antique style buildings is a new structural system,which is the combination of Chinese ancient architecture and modern steel structure.It not only keeps the classical beauty of Chinese ancient architecture,but also has the advantages of good seismic performance and flexible layout of steel structure.The mechanical behavior and seismic performance of steel structure have been studied by scholars at home and abroad.Based on the previous studies,researches on seismic performance and seismic control of Steel beam-column joint in Chinese antique style buildings were systematically studied in this dissertation.Eight specimens in 1:2 scale of double-beams column joints in antique style buildings were designed.Based on the existing beam end restraint device,a unique beam end restraint device of double beams-column joint was designed.The failure process and pattern were observed under low cyclic reversed loading.The strain distribution of core zone,hysteretic loops and skeleton curves were obtained.Mechanical behaviors such as bearing and deformation capacity,degradation of rigidity,energy dissipation capacity were analyzed.The results show that there are 3 small core zones(upper,middle and lower core zone)appeared in the steel double-beams column joint in antique style buildings during loading.The main failure mode is shear failure of the lower core zone under the shear stress and compression stress,as well as the buckling of both sides of the column in the middle core zone.The nonlinear finite element simulation analysis had been done for the aforesaid experimental models by using the software of ABAQUS.The calculated results agree well with experimental results.According to the calculated results,the influence of column axial compression ratio and thickness of core zone of mechanical behavior of double-beams column joints in antique style buildings were analyzed.Based on the test result and finite element simulation result,the mechanism of core zone was studied,a simplified mechanical model and the calculation formulas of shear bearing capacity were proposed.The calculated results agree well with experimental results,which show that the calculation formula is reliable.The technology of seismic control was applied to the steel beam-column joint in antique style buildings.The carved angle brace was replaced by viscous dampers.A new type of damping joint with antique architectural characteristics was designed.This new type of damping joint has combined the technology of seismic control and the carved angle brace which is the special components in the antique architecture.Not only the seismic performance of the joints was improved and the appearance of antique buildings was remained with no change.Based on the test method for seismic behavior of damping joints at home and abroad,the method of cyclic dynamic loading is proposed for the joint with additional velocity damper.Six steel beam-column joints in antique style buildings were designed,which include four specimens with viscous damper and two specimens without viscous damper,the scale model was 1:2.6.The experimental study was carried out by cyclic dynamic loading test.Failure characteristics,mechanical behaviors such as the load-displacement hysteretic loops,skeleton curve,ductility,energy dissipation capacity and rigidity degeneration of the joint were analyzed.The results show that viscous dampers which were attached at the beam-column joint have stable energy dissipation capacity.The steel beam-column joints in antique buildings which installed viscous damper have better energy dissipation capacity and higher bearing capacity.The test of steel beam-column joint in antique style buildings under cyclic dynamic loading was simulated in ABAQUS.The calculated results agree well with experimental results.Based on the FEM model,the influence of column axial compression ratio,damping coefficient,damper length,damper installation angle on the behavior of the new damping joint in antique style buildings which attached viscous damper were obtained.The design suggestions of the new damping joint in antique style buildings which attached viscous damper were presented.