部分充填钢箱—混凝土组合梁变形计算

Slip and deformation calculation of partially filled steel-box-concrete composite girders under negative moment

为研究组合梁负弯矩区的滑移及变形进行了3片不同抗剪连接度的部分充填式钢箱—混凝土组合简支梁试验,观测了在对称集中荷载作用下交界面的相对滑移分布规律和挠度的试验结果。试验结果表明,随着抗剪连接度的增加,滑移逐渐减小且基本上以跨中为对称点沿梁对称分布。建立了考虑滑移效应的组合梁受力模型,推导出部分充填式钢箱—混凝土组合简支梁交界面的滑移微分方程,针对钢结构设计规范运用刚度折减法计算挠度出现的问题,建议采用有效刚度法,同时将计算结果与试验结果进行了对比分析。对比结果表明,在弹性阶段滑移理论计算值和实测值具有很好的拟合性,弹性阶段以后有一定的误差,有效刚度法计算得到的挠度可以准确描述组合梁的变形。

Three partially filled steel-box-concrete composite beam models of different shear connections are tested to study the slip and deformation of partially filled steel box concrete composite Girders under negative moment, and the distribution of relative slip and deflection at the interface under symmetrical concentrated loads are observed. The test results show that the slip decreases with the increase of shear connection, and the slip distributes along the beam symmetrically. The model of partially filled steel-box-concrete composite beam is built considering the effect of slip, and a differential equation of slip at the interface is derived. To solve the problems, the reduced stiffness meth- od is adopted according to the code for the design of steel structures, and the effective stiffness meth- od is suggested. The results of theoretical calculation are compared with the experimental results. Comparison shows that the calculated results and the measured results are in good consistent in the elastic stage, but there are certain errors after this stage. The deflection calculated by the effective stiffness method can describe the deformation of the composite beam accurately.