Reddy高阶组合梁的非线性有限元分析  

NONLINEAR ANALYSIS OF COMPOSITE BEAMS USING REDDY'S HIGHER ORDER BEAM THEORY

作　　者：何光辉[1] 杨骁[1] 

机构地区：[1]上海大学土木工程系,上海200072

出　　处：《工程力学》2015年第8期87-95,共9页Engineering Mechanics

基　　金：国家高技术研究发展计划项目(2009AA032303-2)

摘　　要：该文基于Reddy高阶梁理论,提出了小变形双层组合梁的隐式运动学假定;应用拉格朗日乘子法,将该隐式关系引入到组合梁的最小势能原理,得到了考虑各子梁和粘结滑移层非线性材料特性的高阶组合梁非线性位移法有限单元,且该单元可以容易地转化为非线性Timoshenko和Euler-Bernoulli组合梁有限单元。随后,该研究分别应用提出的Reddy、Timoshenko和Euler-Bernoulli组合梁有限单元对双跨连续钢-混凝土组合梁进行了准静力分析,考察剪切效应对组合梁构件的挠度、粘结层滑移和截面应力的影响,且参数分析了组合梁的跨高比对剪切效应的影响。参数分析表明:短粗组合梁结构往往表现出显著的剪切效应,Newmark假定不再适用。In this study, implicit small deformation kinematics for two-layer composite beams is proposed by using Reddy＇s higher order beam theory （RHBT）. A displacement-based nonlinear finite element for RHBT composite beams is formulated with the help of the modified minimum potential energy principle, in which the proposed implicit kinematics is incorporated through the Lagrangian multiplier method. This finite element also takes into account the nonlinear properties of each sub-layer and shear connectors. In addition, it can easily be reformulated as Timoshenko or Euler-Bernoulli composite beam finite elements. Subsequently, the quasi-static mechanical behaviour of a two-span continuous composite beams is analyzed using the proposed composite beam finite elements based on RHBT, Timoshenko and Euler-Bernoulli beam theories, aiming to examine the shear effects on static behavior, including the deflection, interracial slip and cross-sectional stress of the structure. Moreover, the effects of span-to-depth ratio of composite beams on the shear effects have also been explored by parametric analysis. Results show significant shear effects of composite beams with small span-to-depth ratios, in which case the Newmark model is not applicable.

关 键 词：Reddy高阶梁理论 组合梁 材料非线性 有限元法 剪切效应 

分 类 号：TU323.3[建筑科学—结构工程] TU398.9