时变约束混凝土梁的升降温全过程内力分析  

Analysis of internal forces in inconstantly restrained reinforced concrete beams during heating and cooling phases

作　　者：唐贵和[1,2] 吴波[1] 文波[3] 

机构地区：[1]华南理工大学亚热带建筑科学国家重点实验室,广东广州510640 [2]华南农业大学土木系,广东广州510642 [3]西安建筑科技大学土木工程学院,陕西西安710055

出　　处：《华中科技大学学报（自然科学版）》2015年第1期39-44,共6页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家重点基础研究发展计划资助项目(2011CB013800);国家自然科学基金资助项目(51378225;51025829);中央高校基本科研业务费资助项目(2012ZP001);陕西省百人计划资助项目(陕办发[2009]12号)

摘　　要：利用有限元软件ABAQUS,对时变约束混凝土梁的升降温全过程内力变化进行了探讨.首先考察了梁端轴向和转动约束刚度的变化趋势;然后对单调升温以及先升温后降温情况下,时变约束混凝土梁的轴力和梁端弯矩变化过程进行了计算分析,并与定常约束混凝土梁的相应结果进行了对比.结果表明:高温下时变轴向约束梁的最大轴力比小于定常轴向约束梁,轴向约束刚度比初值越小二者相差越大;高温下时变轴向约束梁的最大梁端弯矩与定常轴向约束梁几乎相同;时变转动约束下梁的轴力比和梁端弯矩随升降温时间的变化曲线都与定常转动约束下的相应曲线一致.Using the finite element analysis program ABAQUS,internal forces in reinforced concrete（RC）beams with inconstant restraints during heating and cooling phases were investigated.First,the changing trends of axial and rotational restraint stiffnesses at beam ends were studied.Then,the variations of axial forces and bending moments in inconstant restrained beams during monotonic heating phase or heating and cooling phases time were analyzed and compared with those in constant restrained beams.Simulation results show that the maximum axial force ratio in an inconstant restrained beam at high temperature is less than that in a constant restrained beam,the less the initial value of axial restraint stiffness is,the larger their difference is;the maximum bending moment at beam end in an inconstant restrained beam at high temperature is almost equal to that in a constant restrained beam;and the variations of axial force ratio and bending moment at beam end in an inconstant restrained beam with heating and cooling time are almost the same as those in a constant restrained beam.

关 键 词：钢筋混凝土 梁 时变约束 升降温 内力 

分 类 号：TU375[建筑科学—结构工程]