基于OpenSees的钢筋混凝土框架节点抗震性能影响因素分析

为了研究低周反复循环荷载作用下混凝土框架节点的抗震性能,本文采用有限元软件OpenSees对其进行数值模拟分析.主要研究了节点核心区混凝土非线性抗剪切性能、核心区梁柱纵筋锚固滑移性能、梁柱混凝土强度等级三方面因素对节点抗震性能的影响.通过对比分析,得出核心区梁柱纵筋锚固滑移性能对节点抗震性能影响最大;节点核心区混凝土应具有足够的抗剪切强度,但盲目的靠提高剪切性能寻求较好的节点抗震性能是没有意义的.核心区抗剪性能的提高应该和粘结强度提高及混凝土强度等级提高等其它因素结合起来,才能很好地提高混凝土框架节点的抗震性能;同时得出梁柱混凝土强度等级对节点抗震性能影响很小的结论.

Analysis of Influencing Factors for Seismic Capacity of Joints in Reinforced Concrete Frame Based on OpenSees

In order to study seismic behavior of joints of reinforced concrete frame under low cyclic and reciprocal loading,using finite element software OpenSees,numerical simulation is carried out in this paper.Three principal influencing factors have been investigated in this paper,including inelastic shear behavior of concrete in core area of joint,anchoring and slipping behavior of longitudinal reinforcement in core area and the strength grade of beam-column concrete.By comparing the results,it is conclued that the anchoring and slipping behavior of bar has greatest effect on seismic capacity of joints.Adequate shear-resist strength of concrete in core area is necessary for the better seismic capacity of joint,but it is insignificant to enhance the seismic capacity only by enhancing the shear strength of shear-panel.Only both enhancing the strength of shear-resist of shear-panel and the strength of bonding of steel with concrete, the better seismic capacity of joints can be get.At the same time,the effect of strength grade of beam-column concrete is very little.