部分充填式钢箱-砼组合梁考虑滑移和剪切变形的变分解法

为研究滑移和剪切变形对部分充填式钢箱-混凝土组合梁变形影响,基于Timoshenk两广义位移理论和能量变分原理,提出组合梁变分计算模型和假定.利用最小势能原理并结合边界条件,分别推导考虑双重变形模式的简支组合钢箱梁负弯矩区滑移微分方程、挠度及附加弯矩的联合弹性解析解.对比两根不同抗剪连接程度组合梁的实测值及理论公式计算值,分析结果表明:在弹性阶段运用变分法推导的挠度及其滑移计算值与实测值相吻合,从而证明了理论公式的有效性.

Energy Variational Method to Analyze Concrete-Partial-Filled Steel Box Composite Beam Considering Shear Deformation and Slip Effect

In order to study the influence of slip and shear deformation to the deformation of concrete-partial-filled steel box composite beams, the differential equations and boundary conditions are established. Based on the generalized displacement theory and energy variational principle of Timoshenk beam, the model and the assumption of the composite beam variational calculation are presented. The combined elastic analytical solutions of the differential equations, deflection and additional moment of the negative moment region of the simple supported composite box girder with double deformation modes are derived by the minimum potential energy principle. Compared with the measured values and theoretical formulas of two composite beams with different shear connection degrees, it’s shown that the deflection and slip calculated by the variational method in the elastic stage agree with the measured values, which proves the validity of the theoretical formula.