【摘要】 对5根预应力内置灌浆方钢管桁架混凝土组合梁进行低周反复荷载下的抗震试验研究。主要参数为综合配筋指标β0、预应力度λ和塑性铰区配箍率ρsv。基于试验,系统地分析了试件的破坏形态、滞回特性、延性、抗力衰减、刚度退化和耗能能力等重要抗震性能。结果表明,综合配筋指标对试件的滞回性能影响明显,当综合配筋指标小于0.2时,试件的位移延性达到4左右,且滞回曲线饱满、具有较好的耗能能力;预应力度主要影响滞回环的饱满程度,对延性有一定影响,但不如综合配筋指标显著;增加塑性铰区配箍率可以增大混凝土极限压应变,提高组合梁延性。更多还原

【Abstract】 An experimental and analytical study of the seismic performance of five prestressed composite beams with encased truss of grout-filled square steel tubes is conducted under low cyclic loading. Global reinforcement index,prestressing level and stirrups ratio in the plastic zone are the main factors in the study. Based on the test results,the failure pattern,hysteretic behavior,ductility,strength degradation,rigidity degeneration,and energy dissipation,etc. are systematically studied. It is found that the influence of global reinforcement on the hysteretic behavior of the specimens is evident. When the global reinforcement index is less than 0.2,the displacement ductility of the specimens is approximately 4,the hysteretic curves exhibit a plump shape,and the specimens possess adequate capacity of energy dissipation. While the prestressing degree affects the area of the hysteretic loop for the most part,its influence on ductility is relatively smaller than that of global reinforcement index. The ultimate compressive strain of concrete and the ductility of the composite beams can be enhanced by increasing the ratio of stirrups.更多还原