自复位钢筋混凝土框架振动台试验的数值模拟

Numerical Simulation of a Self-centering Reinforced Concrete Frame under Shaking Table Test

为了对自复位钢筋混凝土框架结构的抗震性能进行研究,同济大学土木工程防灾国家重点实验室根据相似关系设计与制作了一大比例自复位钢筋混凝土框架,并进行了模拟地震振动台试验。振动台试验模型为单跨两层两榀框架,采用了自复位形式的柱脚节点与梁柱节点,由后张拉无黏结预应力筋提供恢复力。试验选取了El Centro波和汶川波作为单向(X方向)激励输入,研究了结构在多遇地震、基本地震和罕遇地震下的抗震性能。本文主要采用OpenSEES有限元软件对试验模型框架进行数值模拟,并对梁柱节点与柱脚节点提出有效的模拟方法。此外,对该框架进行弹塑性时程分析并与试验实测结果进行对比,对比结果表明本文所提的数值模拟方案能较好地反映试验模型结构的振动特性。

In order to study the seismic performance of self-centering reinforced concrete frame, a large scale model was designed and constructed for shaking table tests in Sate Key Laboratory of Disaster Reduction in Civil Engineering at Tongji University. The self-centering capacity of beam-column joints and column-base joints was achieved by unbonded post-tensioned tendons. Two historical ground motions, E1 Centro wave （1940, NS） and Wenehuan wave （2008, NS） were selected as input ground motions. Both ground motions were applied only in the X-direction. The experimental phenomena were observed and studied under different earthquake levels. In this paper, the behavior of self-centering joints under lateral load was summarized and the numerical method to simulate its performance was introduced. By comparing the result of the experimental results with the simulation, it was indicated that the analytical predictions agreed well with the experimental response.