均布荷载作用下钢管混凝土拱长期稳定性能分析  

Analysis on Creep Stability of Concrete-Filled Steel Tubular Arches under Uniform Load

作　　者：王玉银[1] 吴欣荣[1] 耿悦[1,2] 张素梅[1] 

机构地区：[1]哈尔滨工业大学土木工程学院,哈尔滨150090 [2]悉尼大学土木工程学院

出　　处：《建筑钢结构进展》2011年第6期31-35,43,共6页Progress in Steel Building Structures

基　　金：国家自然科学基金(51178146)

摘　　要：采用ABAQUS有限元软件建立了钢管混凝土抛物线无铰拱模型,利用UMAT引入了钢管混凝土非线性材料应力-应变关系,并采用EC2模型和逐步积分法分析了核心混凝土收缩徐变对拱的平面外稳定的影响,分析中考虑了加载龄期、长细比、矢跨比等参数的影响。分析时先对钢管混凝土拱施加正常使用阶段荷载,持荷一段时间后,增大外荷载直至抛物线拱失稳破坏,从而得到拱的长期稳定承载力。分析表明,长细比、加载龄期及矢跨比等参数变化对钢管混凝土抛物线拱的长期稳定性影响较为显著。低持荷荷载条件下(持荷荷载所引起的核心混凝土最大应力等级为30%),核心混凝土收缩徐变最大可使本文所分析参数范围的抛物线无铰拱稳定极限承载力降低15%。In this paper, a finite element model of concrete-filled steel tubular parabolic hingeless arches is built up with ABAQUS to investigate their creep stability under different loading ages, slenderness ratios and other parameters. In the analysis, the timedependent behaviour of the core concrete is modeled by the EC2 model and step-by-step method and the material nonlinearities under ultimate conditions are also taken into account. The concrete model is introduced into ABAQUS with UMAT subroutine. The lon^term ultimate capacity of arches can be obtained by increasing loads to their failure after the long-term loads are applied for a period. It is shown that the variation of the slenderness ratio,the loading age and rise to span ratio have significant influence on long-term stability of CFST parabolic arches. For arches subjected to low level of long-term loads which causes maximum stress in the core concrete reaching 30 % of the concrete strength, the ultimate capacity of parabolic arches can decrease by 15 %of the instantaneous ones in maximum.

关 键 词：钢管混凝土 抛物线拱 收缩徐变 极限承载力 

分 类 号：TU398[建筑科学—结构工程]