型钢混凝土异形柱框架空间受力性能分析

为研究型钢混凝土异形柱框架的空间受力性能，对一个五层的双向两跨空间框架模型进行了低周反复加载试验，得到了空间框架的破坏形态及滞回曲线和骨架曲线，分析了其延性、位移角、刚度、耗能等抗震性能指标。基于此，采用OpenSees建立了空间框架的有限元模型，计算结果与试验结果吻合较好，进而对空间框架的破坏机制和协同工作机制进行了探讨，并分析了不同加载角下轴压比和柱肢长宽比对空间框架受力性能的影响。研究结果表明:型钢混凝土异形柱空间框架的梁端先于柱端发生破坏，节点损伤相对轻微，边框架的破坏程度比中框架严重；出铰顺序呈现为从梁端到柱端、从低层到高层、从中榀到边榀的发展规律；空间框架的滞回曲线基本对称且较为饱满，具有较好的延性及较强的耗能能力和抗倒塌能力，受力性能优于没有连接的独立框架；随着加载角的增大，空间框架的承载能力和耗能能力显著提高，初始刚度略微增大，延性先变好后变差；在相同加载角下，随着轴压比增大，空间框架的承载能力、延性和耗能能力均降低，初始刚度先增大后减小；随着柱肢长宽比增大，空间框架的承载能力、初始刚度和耗能能力均提高，延性变差。

SPATIAL MECHANICAL PERFORMANCE OF STEEL REINFORCED CONCRETE FRAMES WITH SPECIAL-SHAPED COLUMNS

To study the spatial mechanical performance of steel reinforced concrete frames with special-shaped columns, a five-story two-direction two-span spatial frame model was tested under low cyclic reversed loading. The failure modes, hysteretic curves and skeleton curves were obtained. The seismic performance indexes such as the ductility, story drift ratio, stiffness, and energy dissipation were analyzed. Based on the experimental study, a finite element model of the spatial frame was established by using OpenSees. The analysis results agreed well with the experimental results. The failure mechanism and the cooperative work mechanism were investigated. The influence of the axial compression ratio and column limb length-width ratio under different loading angles were analyzed. The results show that the beam ends failed earlier than the column ends, and the joints were less damaged. The damage of the edge frame was more serious than that of the middle frame. The plastic hinges of the spatial frame developed from the beam ends to the column ends, from the bottom to the top, and from the middle frame to the edge frame. The hysteretic curves were symmetric and full. The ductility was good. The energy dissipation capacity and the collapse resistance were large. The mechanical performance of the spatial frame was better than that of independent frames without connection. With the increment of loading angle, the strength and energy dissipation capacity were obviously increased, the initial stiffness was slightly increased, and the ductility was first increased and then decreased. With the same loading angel and increment of the axial compression ratio, the strength, ductility and energy dissipation capacity of the spatial frame were decreased, and the initial stiffness was first increased and then decreased. With the same loading angel and increment of the column limb length-width ratio, the strength, initial stiffness and energy dissipation capacity of the spatial frame were increased.