关键词: 环梁, 抗震性能, 圆钢管约束 H 型钢混凝土柱, 轴压比, 线刚度比, 变参数 

Abstract:  In this paper，a circular steel tube-confined Hsteel reinforced concrete columnsteel frame ring beam joint was designed，and a fullscale three-dimension finite element analysis model of the specimen was established． Then，the hysteretic curves，skeleton curves and failure modes of the specimens were calculated，and the results were compared with those obtained by experiments，with good accordance being found． Moreover，a finite-element variable parameter analysis was carried out to reveal the effects of axial compression ratio，concrete strength and line stiffness ratio on the seismic behavior of specimens． Finally，an improved node form of beam end-weakening flange was put forward． The results show that ( 1) with the increase of axial compression ratio，the energy dissipation and ductility of the specimen decrease significantly; ( 2) the change of concrete strength has little effect on the hysteretic behavior of specimens; ( 3) the bearing capacity，ductility and seismic energy dissipation performance of the joints all increase significantly with the increase of beam-column linear stiffness ratio when the column section remains unchanged and only the steel beam size varies; ( 4) when the section of steel beam remains unchanged and the steel content in the column varies，the change of seismic behavior of the joint with the line stiffness ratio of beam to column is not obvious; and ( 5) the adoptin of beam end-weakening flange helps to move the plastic hinge far away from the joint area without remarkably reducing the bearing capacity and energy dissipation performance of the specimen，thus protecting the joint area more effectively． The above-mentioned relevant conclusions lay a theoretical foundation for the application of this new type of joint． 

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