基于横向挠度的钢筋屈曲状态判断方法研究  

RESEARCH ON BUCKLING STATE DETERMINATION OF REINFORCING BARS BASED ON LATERAL DEFLECTION

作　　者：刘子珅 杨红[1,2] 张吉庆 

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400045 [3]重庆市设计院,重庆400015

出　　处：《工程力学》2018年第2期144-152,共9页Engineering Mechanics

基　　金：国家自然科学基金项目(51178487)

摘　　要：现有钢筋材料试验、混凝土构件性能试验一般通过肉眼观察得到钢筋受压后开始弯曲的屈曲开始点,该方法缺乏客观性、准确性。该文以单根钢筋循环拉压试验的量测数据为基础,通过分析钢筋试件中点处两正交方向横向挠度的相关性以及屈曲钢筋总横向挠度的变化规律,结合Rodriguez等提出的基于钢筋凸侧与凹侧的应变差计算结果的判断方法,提出了三种判断屈曲开始点的方法,即基于屈曲钢筋总横向挠度测量结果的"观察法"、"临界横向挠度"法,以及基于总横向挠度变化量的"临界横向挠度变化量"法。采用这三种方法判断35个钢筋循环拉压试验的屈曲开始点,结果表明将"临界横向挠度"法和"临界横向挠度变化量"法的结果相结合可以更合理、准确地判断屈曲开始点。In existing material tests of steel bars and experimental studies on reinforced concrete components, it is common to define the beginning of bar bending under compression as the onset of buckling through visual observation, which is arbitrary and inaccurate. Based on the experimental results of cyclic tension-compression tests of steel bars, the correlation of lateral deflections in two orthogonal directions and the variation of the total lateral deflection are studied. Combined with Rodriguez＇s suggestion which uses the strain difference of opposite faces （concave side and convex side） of a specimen, three determination methods are proposed to predict the onset of buckling, namely “observation method”, “critical lateral deflection” method and “critical variation of lateral deflection” method. They are based on visual observation, the measurement of total lateral deflection and its variation, respectively. The analysis of 35 cyclic loading tests of steel bars using the three methods indicates that a combination of the “critical lateral deflection” method and the “critical variation of lateral deflection” method can predict the onset of buckling more reasonably and accurately.

关 键 词：钢筋混凝土柱 纵向钢筋 屈曲 滞回性能 非线性 

分 类 号：TU375[建筑科学—结构工程]