底部加强矩形钢管混凝土柱抗震性能优化分析

为优化分析矩形截面钢管混凝土柱抗震性能影响参数，提出在底部外侧贴焊钢板的加强矩形钢管混凝土柱。在试验基础上用ABAQUS软件对轴压比、混凝土强度等级、底部加强钢板高度及厚度对试件影响进行数值分析，并与试验对比。结果表明，随轴压比增大试件承载力、延性逐步下降；随混凝土强度等级提高试件承载力提高，但下降段变陡，延性降低；随加强钢板高度增加试件承载力稳步增大，耗能能力提高，延性近似相等；随加强钢板厚度增加承载力提高幅度有限。在满足构造要求下，底部加强矩形截面钢管混凝土柱结构综合抗震耗能良好，可用于高层建筑结构抗震设计。

Numerical analysis for the seismic performance of bottom strengthened retangular concrete filled steel tube columns

In order to optimize the influencing parameters of seismic performance about rectangular concrete filled steel tube (CFST) column, a bottom strengthened rectangular CFST column whose bottom zone was welded with enhancing steel plates, was proposed. Based on the experimental results, the factors affecting the load-bearing capacity were analyzed. By means of the finite element analysis software ABAQUS, the analysis to simulate numerically the specimens with different compression ratio, different strength grade of concrete, different height and thickness of the bottom strengthened steel plate were carried out. The analytical results were compared with the experimental results. The study shows: when the axial compression ratio increases, the load-bearing capacity and the ductility decrease; when the strength grade of concrete increases, the bearing capacity also increases, but the decline steepens and the ductility decreases; when the height of the strengthened plate increases, the load-bearing capacity of specimens increases steadily, the energy dissipation capacity increases, and the ductility is approximately equal to each other; when the thickness of the strengthened plate increases, the load-bearing capacity improves only a little. The rectangular concrete filled steel tube column with bottom enhancing plates shows better seismic behavior and higher energy dissipation capacity if suitable constructional requirements are satisfied. Such structural configuration can be adopted in design of high-rise buildings.