考虑钢筋混凝土梁柱节点受力特征的钢筋锚固受力性能试验  

Experimental Research on Anchorage Performance of Rebars Considering Mechanical Characteristics of RC Beam-Column Joints

作　　者：杨红[1] 刘清培 杨小乙[2] YANG Hong;LIU Qingpei;YANG Xiaoyi(School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area of China Ministry of Education,Chongqing University,Chongqing 400030,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]山地城镇建设与新技术教育部重点实验室(重庆大学),重庆400030

出　　处：《工业建筑》2022年第4期40-49,97,共11页Industrial Construction

基　　金：国家自然科学基金项目(52078078)。

摘　　要：强烈地震作用下梁纵筋在钢筋混凝土梁柱节点内一般会产生明显的黏结滑移变形,通过合理的材料本构模型正确描述节点内梁纵筋的黏结滑移规律是节点单元有限元模型的关键问题。在“超级节点”单元模型和OpenSees软件中,梁纵筋的应力-滑移本构模型是在传统单根钢筋锚固的单调受拉试验基础上建立的,未考虑轴压力、循环拉压等对节点内梁纵筋受力的影响。对11个锚固钢筋试件在单调受拉、循环拉压等加载方式下的受力性能进行了试验,测量了钢筋的黏结滑移变形,通过对比锚固钢筋的应力-滑移试验结果,分析了加载方式、轴压力、相对锚固长度、钢筋屈服强度等对滑移变形的影响。研究结果表明,单调受拉时钢筋的锚固性能相对最好,拉-拉循环加载时锚固钢筋的黏结滑移变形更大,拉-压循环加载会进一步加大锚固钢筋的滑移变形;施加轴压力有利于提高锚固钢筋的黏结性能、减小黏结滑移变形;增加钢筋的相对锚固长度,钢筋受拉屈服时的滑移变形将减小;基于锚固钢筋的单调受拉试验建立的材料本构模型未考虑轴压力、加载方式的影响,难以合理模拟节点内梁纵筋在强烈地震作用下的滑移变形。The longitudinal steel bars of beams generally produce a obvious bond-slip deformation in reinforced concrete(RC)beam-column joints under strong earthquake excitation.The key issue of finite element model of RC joint is to correctly describe the bond-slip laws of longitudinal steel bars of beams based on a reasonable material constitutive model.In the“super joint”model and OpenSees software platform,the stress-slippage constitutive model for longitudinal steel bars of beams was established on the basis of monotonic tensile test for traditional anchorage of single steel bars,the influence of axial compression and cyclic tension-compression on the anchorage performance of the longitudinal steel bars of beams in the joint was not considered.The mechanical properties of 11 specimens were tested under monotonic tension or cyclic tension-compression,and the bond-slip deformations of the bars were measured.By comparing the stress-slippage test results of the anchorage steel bars,the effects of loading method,axial compression,relative anchorage length and yield strength of the steel bars on the slip deformation were analyzed.The results showed that the anchorage performance of the steel bars was relatively the best under monotonic tension,the bond-slip deformation of the steel bars was larger under tension-tension cyclic loading,and the slip deformation of the steel bars would be further increased under tension-compression cyclic loading.The application of axial compression load was beneficial to improve the bond performance of the steel bar,and reduce the bond-slip deformation.With the increase of the relative anchorage length,the slip deformation of the steel bars at the tensile yield would decrease.The material constitutive model based on the monotonic tensile test of anchorage steel bar did not consider the influence of axial compression and loading method,it was difficult to reasonably simulate the slip deformation of longitudinal steel bars of beams in RC joints under strong earthquake.

关 键 词：梁柱节点 纵筋 黏结滑移 轴压力 加载方式 有限元模型 

分 类 号：TU375[建筑科学—结构工程]