采用黏滞流体消能器加固的框架结构抗震性能分析

Seismic performance analysis of a frame structure strengthened with viscous fluid damper

对采用黏滞流体消能器(VFD)加固的某钢筋混凝土框架结构的抗震性能进行了研究。首先对采用不同阻尼系数和速度指数的VFD进行加固时结构的附加阻尼比进行了比较,得到了较为合适的VFD参数。接着采用MSC.MARC软件对原结构和加固后的结构进行了动力弹塑性时程分析与比较研究,开发了用于模拟钢筋混凝土框架梁与柱的纤维梁单元子程序,采用分层壳单元模拟钢筋混凝土楼板,对未加固和加固后的结构位移、层间位移角等进行了考察,对VFD的地震反应进行了分析,并对关键构件的应变-应力滞回关系进行了分析。分析结果表明,未加固结构在罕遇地震下存在倒塌的风险,增设VFD可显著提高结构的抗震能力,结构达到了"大震不倒"的抗震设防目标。

Seismic performance of a reinforced concrete frame structure strengthened by viscous fluid damper （VFD） was studied. At first, additional damping ratios of the VFD strengthened structure with different damping coefficients and velocity coefficients were compared to find the appropriate VFD coefficient, Then, dynamic elastic-plastic time history analysis was performed to analyze, compare and study the original structure and strengthened structure based on the program of MSC. MARC. User subroutine of fiber beam element used to simulate reinforced concrete columns and beams was developed. Multi-layer shell element was used to simulate reinforced concrete slab. Displacement and inter-story drift of both the original structure and strengthened structure were studied. Seismic response of VFD was investigated. Strain-stress hysteretic relationships of critical opponents were also analyzed. The analysis results show that there exists collapse risk for original un-strengthened structure subjected to rare earthquake. Seismic performance of the structure can be significantly improved by supplemental VFD. The third level seismic fortification objective which was ＂ no-collapse under rare earthquake＂ of the strengthened structure can be achieved.