摘要
共进行了9根钢-混凝土组合箱梁的扭转试验,其中4根用于研究纯扭性能,5根用于研究弯扭性能,初步掌握了该类型梁的抗扭机理。组合箱梁截面通过两种机制抵抗截面扭矩:U形钢梁和混凝土翼板组成的组合箱形截面(称为组合抗扭),及混凝土翼板开裂后形成的等效箱形截面(称为混凝土翼板抗扭)。组合箱梁在扭转中,截面上存在组合作用,即混凝土翼板和钢梁间存在相互约束作用。U形钢梁的抗扭贡献在于:它不仅作为组合箱形截面的重要组成部分,自身承担较大的扭矩,而且向混凝土翼板提供纵向约束,抑制混凝土裂缝的开展。在试验分析的基础上,采用钢筋混凝土变角软化桁架模型,建立了适于分析钢-混凝土组合箱梁复合弯扭强度的三维桁架模型。该模型充分满足平衡条件、变形协调条件和材料本构方程,可以较准确地用于预测组合箱梁的极限强度。此外,还对组合箱梁的弯扭相关强度进行了研究。
Nine steel-concrete composite box girders, four under pure torsion and five under combined bending and torsion were tested to study their torsional behaviors. Tests results showed that the composite box girder resists external torque by two mechanisms： one is the composite box section comprising U-joist and concrete flange, the other is the equivalent box section which is developed in the cracked concrete flange. And the composite action between joist and concrete flange definitely exists in the composite girder subjected to torsion. The contribution of U-joist lies that it carries considerable torque as a part of the composite box section, as well as restrains concrete flanges from deforming longitudinally. According to test results, using the rotating-angle softened truss model （RA-STM）, a three- dimensional behavioral truss model cable of analyzing the torsional strength of such girders under combined bending and torsion, is presented. This model, which satisfies the equilibrium equations, compatibility equations and the constitutive laws of materials, can accurately predict the torsional strength of specimens. Additionally, the interaction between bending and torsional strengths is discussed.
出处
《土木工程学报》
EI
CSCD
北大核心
2008年第1期1-11,共11页
China Civil Engineering Journal
基金
国家自然科学基金(50438020)
长江学者和创新团队发展计划
关键词
钢-混凝土组合箱梁
试验
复合弯扭
变角软化桁架模型
抗扭强度
steel-concrete composite box girders
experiments
combined bending and torsion
rotating-angle softened truss model
torsional strength
作者简介
聂建国（1958-），男，博士，教授。主要从事组合结构研究。聂建国，博士，教授E-maih niejg@mail.tsinghua.edu.cn
唐亮（1981-），男，博士研究生。主要从事组合结构研究。
胡少伟（1969-），男，博士，教授级高工。主要从事组合结构研究。
朱红超（1975-），男，硕士。主要从事组合结构研究。
