栓钉连接件时变受剪承载力对组合梁施工阶段受力性能的影响

为了对钢-混凝土组合梁施工阶段的受力性能进行准确分析，针对我国常用的隔板式组合梁，通过推出试验研究栓钉连接件受剪承载力随混凝土龄期的变化规律，采用ANSYS有限元分析软件分析栓钉连接件时变受剪承载力对某连续曲线组合梁施工阶段受力性能的影响。分析结果表明：在混凝土龄期很短时栓钉连接件就具有一定的受剪承载力和抗剪刚度，且早期增长快，后期增长慢；混凝土板分段浇筑时组合梁的应力和变形随浇筑时间间隔的增加逐渐减小，在本文实例中，与不考虑浇筑过程中混凝土与钢梁的组合作用时相比，浇筑时间间隔为6 h的组合梁径向变形减小26.5%；与考虑28 d龄期混凝土与钢梁的组合作用时相比，浇筑时间间隔为3 d的组合梁切向应力增大14.2%。因此，当组合梁混凝土板浇筑时间间隔在6 h至3 d之内时，均应采用栓钉连接件的时变受剪承载力来分析浇筑过程中混凝土与钢梁的时变组合作用对组合梁施工阶段受力性能的影响。

Effect of stud connector's time-dependent shear strength on behavior of steel-concrete composite beams in construction stage

In order to analyze the behavior of the steel-concrete composite beams in construction stage accurately, the law of the stud connector’s shear strength with the concrete age was researched by the push-out test. The effect of the stud -connector’s time-dependent shear strength on the behavior of a continuous curved composite beam in construction stage was analyzed using ANSYS FE analysis software. The analysis results indicate that, the shear strength and stiffness of stud connectors can not be ignored even the concrete age is rather short. The early shear strength increases more quickly, while the later shear strength increases more slowly. The stress and deformation of the curved composite beams in construction stage decrease with the increase of the concrete casting time interval. For the example in this paper, the radial deformation of the composite beam with the casting time interval of 6 h, decreases 26.5% compared to the result of the composite beam without composite action, and the tangential stress of the composite beam with the casting time interval of 3 d, increases 14.2% compared to that of 28 d. If the concrete casting time interval of the composite beam is from 6 h to 3 d, the stud connector’s time-dependent shear strength should be used to analyze the behavior of the composite beams in construction stage.