考虑冻融损伤的钢筋混凝土框架节点恢复力模型研究

发布时间：2018-05-02 01:44

本文选题：钢筋混凝土 + 框架节点　；参考：《工程力学》2017年05期

【摘要】：为了研究冻融环境下钢筋混凝土框架节点的抗震性能,对6个经受不同冻融循环次数作用后的钢筋混凝土框架节点进行低周反复加载试验,分析框架节点的滞回曲线特性。基于试验结果,得到了简化三折线型骨架曲线模型,并给出了相应的确定方法。采用回归分析方法,得到考虑冻融损伤的钢筋混凝土框架节点的极限功比系数I数学表达式,进而确定基于循环耗能的循环退化指数,通过对构件在反复荷载作用下的屈服荷载、硬化刚度、卸载刚度以及承载力等各项力学性能的退化机理进行了描述,进一步建立适应于冻融损伤的钢筋混凝土框架节点的恢复力模型,并给出了具体的滞回曲线规则。研究表明:冻融作用使得节点梁纵筋粘结性能劣化明显,累积耗能随着冻融循环次数的增加而降低;通过考虑刚度、强度的循环退化规律能更好的反应冻融节点"捏缩"效应,更与实际吻合;建议的恢复力模型与试验结果想接近,可为该类结构的弹塑性时程分析提供理论参考。
[Abstract]:In order to study the seismic performance of the reinforced concrete frame joints under the freezing thawing environment, 6 reinforced concrete frame joints subjected to different freezing and thawing cycles were tested in low cycle repeated loading tests to analyze the hysteresis curve characteristics of the frame joints. Based on the test results, the simplified three fold line skeleton curve model was obtained and the phase was given. The regression analysis method is adopted to obtain the I mathematical expression of the limit work ratio coefficient of the reinforced concrete frame joints with freeze-thaw damage, and then determine the cyclic degradation index based on the cyclic energy dissipation, and through the yield load, stiffness, unloading stiffness and bearing capacity of the members under repeated loads. The degradation mechanism of the performance is described, and the restoring force model adapted to the freeze-thaw damage of the reinforced concrete frame joints is further established, and the specific hysteresis curve rules are given. The study shows that the freezing thawing effect makes the bond performance of the beam longitudinal reinforcement worse, and the cumulative energy consumption decreases with the increase of the number of freezing and thawing cycles; Considering the stiffness, the cyclic degradation of strength can better respond to the "kneading" effect of the freezing and thawing nodes, which is more consistent with the practice. The proposed restoring force model is close to the experimental results, which can provide theoretical reference for the elastoplastic time history analysis of this kind of structure.

【作者单位】：西安工业大学建筑工程学院;西安建筑科技大学土木工程学院;
【基金】：国家科技支撑计划基金项目(2013BAJ08B03) 教育部高等学校博士学科点专项科研基金项目(20136120110003) 陕西省教育厅科研计划项目(15JK1357)
【分类号】：TU375.4

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