低周反复荷载下预压装配式PC框架延性性能和耗能能力

通过两榀两跨预压装配式预应力混凝土框架在低周反复荷载作用下的试验,探讨了预压装配式预应力混凝土框架的承载能力、破坏形态、滞回性能、变形恢复能力、截面延性及耗能能力等抗震性能。试验研究表明:仅依赖预应力筋抗弯的梁端截面,滞回曲线较为丰满,具有良好的耗能能力;曲率延性系数达4时,截面承载力无明显降低,可满足弯矩调幅要求;卸载后残余变形较小,截面屈服后仍具有变形恢复能力;对称和反对称两种加载方式对跨中和梁端受力性能和延性无明显影响,仅对中柱节点核心区受力状态产生较大影响。

Behavior of ductility and energy dissipation of prestressed precast concrete frame under low-cyclic reversed loading

Two double-span prestressed precast concrete(PC) frame were tested under low-cyclic reversed loading,in order to study the load-bearing capacity,failure mechanism,as well as the seismic behavior of hysteresis curves,energy dissipation,restoring capacity,ductility.The results showed that the beam ends where placed only prestressed wires have full hysteretic loops and better energy dissipation capacity.The load carrying capacity would not degrade before the curvature ductility coefficient up to 4,which was suitable for moment modulation.The PC connection at beam ends have small residual displacement and sufficient restoring capacity that reduce the frame deformation in earthquake and can be repaired conveniently if damaged.The load carrying capacity and ductility behavior of the beams have no difference under symmetry loading or antisymmetry loaging.These two loading patterns differ greatly in shear capacity in the core area of connections of the interior column.