配置核心钢管的钢筋混凝土柱-钢骨混凝土梁组合框架抗震性能试验研究

进行两榀配置核心钢管的钢筋混凝土柱-钢骨混凝土梁组合框架试件在水平低周往复荷载作用下的试验研究，观察试验过程及破坏形态，研究试件的滞回特性、骨架曲线、刚度退化、耗能能力、残余变形等抗震性能，同时对梁柱端纵筋、钢骨翼缘及钢管在不同加载位移下的应变变化规律进行分析，得到框架结构的出铰顺序。研究结果表明：两榀框架滞回曲线饱满，施加预应力后仍具有较好的耗能能力和延性，表现出良好的抗震性能；框架柱底塑性铰区的钢管环向应变在整个加载过程中呈不均匀变化趋势，截面受压区钢管环向受拉，能够对受压区混凝土提供有效约束；钢骨混凝土梁由于施加预应力的作用，可延缓其裂缝的出现；此外，两榀框架试件均呈现“先梁端后柱底”的出铰顺序，能实现梁铰耗能机制，延迟柱底出铰时刻。

Test on seismic performance of frame structure of steel reinforced concrete beam and steel-tube encased concrete column

This paper conducted a test on two frame structures of steel reinforced concrete beam and steel-tube encased concrete column under horizontal low cyclic loading. The test process and failure mode were observed, and the hysteretic behavior, skeleton curves, stiffness degradation, energy dissipation, and residential deformation of the two frames were studied. Meanwhile, the law of strain values of longitudinal bars, flanges and steel-tube in the beam and column end was analyzed carefully, and the order of plastic hinges was given. The test results show that hysteretic curves of the two specimens are plump, and one also behaves good energy dissipation when it is prestressed, and they behave good seismic performance. Meanwhile, the hoop strains of steel-tube of plastic hinge in the column bottom changes unevenly during the whole loading, and they could supply effective constraint on compressive concrete. And the cracks could be delayed when the steel reinforced concrete beam is prestressed. Furthermore, the sequence of plastic hinges of the two specimens is ‘beam ends before and column bottoms after’, so that the mechanism of energy dissipation for beam plastic hinges and a delayed occurring of plastic hinges for column bottom could be achieved.