考虑界面滑移与剪切变形的钢-混凝土组合梁解析方法

Analytical Method of Steel-Concrete Composite Beam Based on Interface Slip and Shear Deformation

为求解钢-混凝土组合梁在界面滑移与剪切变形双重影响下的变形与应力,本文引入Timoshenko梁双广义位移假定,建立了钢-混凝土简支组合梁弹性状态下的计算模型,并以跨中作用集中荷载为例,得到其全梁挠度与截面应力的解析解。同时对4根不同抗剪连接程度的钢-混凝土组合梁试验结果进行分析,与解析计算结果进行对比验证,并讨论了界面剪切刚度的取值对组合梁挠度的影响。结果表明理论计算所得挠度、应力均与试验值吻合良好;界面滑移将增大组合梁挠度,界面剪切刚度对这种增大效应有重要影响;在计算组合梁挠度时,忽略剪切变形在一定程度上不安全。

To solve the deformation and stress of the steel-concrete composite beam under the impact of interface slip and shear deformation,Timoshenko beam assumption is introduced to establish theoretical calculating model of simple steel-concrete composite beam in elastic state,which leads to the analytical solutions of deflection and section stress under mid-span concentrated load.By analyzing the test results of four simple composite beams with different connection degrees and comparing it with theoretical results,the value and the influence on deflection of interfacial shear stiffness are discussed.Results show that(1)theoretical results and experimental data are in good agreement;(2)the interface slip increases deflection,and the interfacial shear stiffness has an obvious influence on it;(3)neglecting shear deformation is unsafe to some extent when calculating the deflection of the composite beam.