T形配钢型钢混凝土柱-钢梁框架抗震性能研究

为研究T形配钢型钢混凝土柱-钢梁框架的抗震性能,进行了1榀3层2跨、缩尺比例为1∶3的框架试件拟静力试验,了解其破坏形态、滞回曲线和骨架曲线,分析了试件的延性、耗能能力、刚度和强度退化规律。基于纤维模型对框架试件进行了数值模拟,研究了结构抗震性能在不同轴压比、配钢率和混凝土强度下的变化规律。结果表明:在水平低周往复荷载作用下,试件出现"梁铰"破坏,具有良好的延性和耗能能力,满足"强柱弱梁,强剪弱弯,强节点弱构件"的抗震设计要求。轴压比对试件屈服后的性能影响较大,结构的承载力和延性随轴压比增大而有所降低,设计时需合理控制轴压比;配钢率主要影响初始刚度和极限承载力,结构的抗震性能随配钢率增大得到有效改善;结构的极限承载力随着混凝土强度增大而提高,但结构的延性会略有降低,设计时需合理考虑。研究成果可为该类结构的设计提供可靠的支撑。

RESEARCH ON THE SEISMIC BEHAVIOR OF FRAME STRUCTURES WITH T-SHAPED STEEL REINFORCED CONCRETE COLUMNS AND STEEL BEAMS

To study the seismic behavior of frames with T-shaped steel reinforced concrete columns and steel beams, a pseudo-static test of a 1/3 scaled, 3-story 2-bay specimen was carried out. The main results such as the failure pattern, hysteretic and skeleton curves were obtained. The ductility, energy dissipation capacity and degradation of stiffness and strength of the specimen were analyzed. Numerical simulations were conducted with the fiber model to study the effects of different design parameters such as the axial compression ratio, steel ratio and concrete strength on the seismic performance of the frame. It was demonstrated that the specimen exhibited a beam-hinge failure mode under the condition of horizontal cyclic loading. The specimen had good ductility and energy dissipation capacity and it met the seismic design requirements of strong column-weak beam, strong shear-weak bending and strong joint-weak pole. The axial compression ratio has great influence on the performance of the specimen after yielding. With the increase of the axial compression ratio, the strength and ductility of the structure will decrease. It is necessary to control the axial compression ratio in a reasonable range in the design. The steel ratio mainly affects the initial stiffness and ultimate strength, while its increase can effectively improve the seismic performance of the frame. The increase of concrete strength can increase the ultimate strength of the structure, but reduce the ductility slightly. It is of great significance to consider concrete strength comprehensively in the design. The research results can provide reliable support for the design of this kind of structures.