疲劳荷载作用下钢筋混凝土梁的刚度退化规律及计算公式  

Reinforced Concrete Beam's Stiffness Degeneration Regulation and its Calculation Formula Under the Action of Fatigue Load

作　　者：朱红兵[1,2] 赵耀[1] 李秀[3] 余志武[2] 

机构地区：[1]武汉科技大学城市建设学院武汉430070 [2]中南大学土木工程学院,长沙410075 [3]武汉理工大学华夏学院,武汉430223

出　　处：《土木建筑与环境工程》2014年第2期1-5,13,共6页Journal of Civil,Architectural & Environment Engineering

基　　金：国家西部交通建设科技项目(200631800019);国家863计划(2009AA11Z101);湖北省自然科学基金(2011CDB239)

摘　　要：对承受疲劳荷载反复作用的钢筋混凝土结构而言,疲劳是一种重要的损伤形式,如何判断和描述其损伤程度是结构损伤与寿命评估领域的一大难题。结构刚度会随损伤发展而逐渐发生不可逆的退化,刚度退化与疲劳损伤之间存在一定的内在关联,且刚度测试简单易行,开展了一系列的疲劳试验研究刚度退化规律和计算方法。通过疲劳试验观测,钢筋混凝土梁刚度退化呈现出非常明显的三阶段规律,刚度退化曲线符合"S"型形态。根据刚度退化规律对试验数据进行拟合,得到可用于计算钢筋混凝土梁刚度退化程度的公式,该公式与10根试验梁的试验结果吻合度较好,能够实现对刚度退化的描述。利用钢筋混凝土梁刚度退化计算公式,可以预测结构在服役过程中的变形发展情况,也可以进行结构疲劳损伤、性能退化程度判定及剩余寿命预测。Fatigue failure is a fatal damage for the reinforced concrete structure bearing fatigue load repeatedly. That how to estimate or describe the degree of fatigue damage is a challenge in areas of structure damage and lifespan estimation. Structure＇s stiffness degenerates irreversibly along with the damage progress. There is a certain inherent relevance between stiffness degeneration and fatigue damage. A series of fatigue tests were carried out to study stiffness degeneration regulation due to its simplicity and feasibility. According to the test results, reinforced concrete beam＇s stiffness degeneration presents a three-stage rules obviously, and the stiffness degeneration curves accord with ＂ S＂ style. Based on the stiffness degeneration regulation, the reinforced concrete beams＇ stiffness degeneration calculation formula is obtained by fitting experimental data. The formula has a perfect goodness of contact area with 10 test beams＇ experimental results, and it can describes reinforced concrete beams＇ stiffness degeneration perfectly. The formula can be used to forecast the deformation developing. Meanwhile, the residual life of the structure can be used to decision structure＇s fatigue fracture and the degree of performance degradation.

关 键 词：疲劳荷载 刚度退化 计算公式 钢筋混凝土梁 

分 类 号：U441.4[建筑科学—桥梁与隧道工程] U448.34[交通运输工程—道路与铁道工程]