建筑钢筋动态试验及本构模型  

Dynamic test and constitutive model for reinforcing steel

作　　者：李敏[1] 李宏男[1] 

机构地区：[1]大连理工大学,辽宁大连116024

出　　处：《土木工程学报》2010年第4期70-75,共6页China Civil Engineering Journal

基　　金：国家自然科学基金重大研究计划重点项目(90815026);高等学校学科创新引智计划(B08014);国家"十一五"科技支撑计划重大项目(2006BAJ03A03);重点项目(2006BAJ06B03);地震行业科研专项目(20080874);教育部创新团队基金(IRT0518)

摘　　要：利用MTS New 810电液伺服材料试验机,对不同强度的建筑钢筋在地震作用应变率范围(2.5×10-4/s～0.1/s)内的动态特性进行了试验研究。采用单调拉伸、常幅值循环和变幅值循环三种加载方式,加载过程由应变控制并保持应变率恒定。试验结果表明,钢筋的力学和变形性能在不同加载方式下均有应变率敏感性,应变率敏感性的大小与准静态屈服强度密切相关,相同应变率下循环加载的骨架曲线与单调加载的拉伸曲线基本重合。对试验数据进行回归分析,得到了钢筋的力学性能特征值和变形性能特征值随应变率变化的规律,进而结合Hoehler模型提出了一种钢筋动态循环本构模型,与试验结果对比表明该模型能很好地描述钢筋的动态行为,建议的钢筋动态本构模型可以应用在钢筋混凝土结构抗震分析中。Dynamic properties of reinforcing steels of various strengths were investigated by using a MTS New 810 electro-hydraulic servo-controlled testing system with a range of strain rate between 2.5 × 10^-4/s and 0. 1/s, which covers the range that might be experienced during earthquakes. Three types of loading conditions were adopted： monotonic tensile loading, constant amplitude cyclic loading and variable amplitude cyclic loading, and strain control was applied with the strain rate being kept as constant during loading. Test results show that the mechanical and deformation properties of reinforcing steels are sensitive to strain rate under different loading conditions, that the quasistatic yield strength has significant influence on the strain rate effect, and that the skeleton curve under cyclic loading and the tensile curve under monotonic loading are almost coincident at the same strain rate. Based on the test data, the relationships between mechanical and deformation characteristic values and strain rate are built, respectively, and a ratedependent cyclic constitutive model of reinforcing steel is developed through improving the Hoehler model. Comparing with the experimental results, the proposed model can describe the dynamic characteristics and can be used for seismic analysis of reinforced concrete structures.

关 键 词：钢筋 地震作用 应变率 动态循环本构模型 

分 类 号：TU511.32[建筑科学—建筑技术科学]