多腔矩形钢管-混凝土异形柱框支结构抗震性能有限元分析

Finite Element Analysis on Seismic Behavior of Multi-Cavity Rectangular CFST Column Braced Frame Structure

本文提出了一种多腔矩形钢管混凝土异形柱-H型钢梁-H型钢支撑框架支撑结构,研究该种框支结构体系的抗震性能。基于ABAQUS建立了9组框支结构的有限元模型,通过对已有试验中的两层两跨框架模型进行模拟分析,验证了有限元结果的正确性与合理性,进而对新提出的钢管-混凝土异形柱框支结构的受力性能进行了数值模拟分析。通过改变模型的轴压比、异形柱钢管与混凝土强度、不同的支撑设置形式,得出各组结构体系模型的滞回曲线、骨架曲线及刚度退化曲线等,并分别对其进行延性与耗能分析。模拟分析结果表明:较高的轴压比有利于正向承载力、延性及耗能性能的增加,但负向承载力及刚度降低;更高的混凝土强度对延性及耗能影响不明显,但承载力增大;当提高钢材强度时,延性及耗能能力略有降低,正向承载力差异不大,但负向承载力体现出较大差异;双X支撑形式较双人形支撑及人-V形支撑具有更优的抗震性能指标。该种异形柱框支结构体系具有良好的抗震性能,可以应用于工程实际中。

A braced frame structure system composed of multi-cavity rectangular concrete-filled steel tubular columns,H-shaped steel beams,and H-shaped steel brace is proposed in this paper.In order to study the seismic behavior of this braced frame structure system,a finite element model of 9 groups was established based on ABAQUS.The simulation analysis of the seismic behavior of the two-story,two-span frame model in the existing experiments verified the correctness and rationality of the finite element calculation results,and then the numerical simulation analysis of the mechanical performance of the newly proposed braced frame structure was performed.By changing the axial compression ratio in the model,the strength of steel tube and concrete of the special-shaped column and the different support settings,the hysteresis curve,envelop curve,and stiffness degradation curve of each group of structural system models are obtained,and the ductility and energy consumption are analyzed separately.The simulation analysis results show that a higher axial compression ratio is beneficial to the increase of positive bearing capacity,ductility,and energy consumption performance,but the negative bearing capacity and stiffness decrease.Higher concrete strength has no obvious effect on ductility and energy consumption,but the bearing capacity.When the strength of steel is increased,the ductility and energy consumption capacity are slightly reduced,and the difference in positive bearing capacity is not large,but the negative bearing capacity shows a large difference.Compared with the double herringbone brace and the herringbone-V shape brace,the double X-brace form has better seismic performance indicators.Therefore,the special-shaped column braced frame structure system has good seismic performance and can be applied to practical engineering.