摘要
以广义徐变系数为基础,推导了普通混凝土在长期荷载作用下的徐变应力-应变计算公式,结果表明可以将应变作为混凝土徐变计算的基本变量,并在合理假设下推导证明可以将核心混凝土的自由徐变应变作为钢管混凝土徐变计算的基本变量。提出了等效温度荷载法计算钢管混凝土徐变,基于有限元软件ANSYS,采用等效温度荷载法将修正后的3种典型的混凝土徐变系数模型用于长期轴压荷载作用下钢管混凝土构件的徐变性能分析。计算值与试验实测值对比表明:等效温度荷载法可以用于计算长期荷载作用下普通钢管混凝土和钢管膨胀混凝土的徐变;MC90模型和EC2模型计算值与长期荷载作用下钢管混凝土构件徐变试验实测值吻合良好;GL2000模型高估了钢管混凝土构件徐变应变。
Based on the generalized creep coefficient, the calculation formula of creep stress and strain of concrete under long-term loading is derived. The formula shows that it is feasible to use strain as basic variable for creep calculation of concrete. Based on reasonable hypothesis, it is proved that the freedom creep strain of the core concrete can be regarded as basic variable to calculate the creep property of concrete-filled steel tubular （CFST） members under long-term loading, and the equivalent thermal load method is proposed to calculate the creep of CFST. Three typical concrete creep coefficient models are modified to analyse the creep of axially compressed CFST members under long-term loading by equivalent thermal load method and the finite element soft ANSYS. The comparison between the analysis and the test results indicates that （ 1 ） equivalent thermal load method is suitable for calculating the creeps of ordinary and expansive CFST members under long-term loading; （2） the calculated creep values using MC90 model and EC2 model are well agree with the measured creep values of the CFST members under long-term loading; （3） GL2000 model overestimated the creep strain of CFST members.
出处
《公路交通科技》
CAS
CSCD
北大核心
2013年第4期46-52,共7页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(51208431)
教育部高等学校博士学科点专项科研基金项目(20090184120033)
中央高校基本科研业务费专项资金项目(SWJTU12CX064)
