全装配式钢-混凝土组合构件抗剪性能试验研究

Experimental Study on Shearing Resistance of Fully Assembled Steel-Concrete Composite Structures

为探索全装配式剪力钉(PCSS)的力学性能,设计了大比例PCSS剪力连接构件并进行推出试验。试验结果表明:大比例PCSS剪力连接件分3阶段受力,①弹性阶段:当0<P≤0.5P u时,PCSS剪力钉荷载-滑移曲线斜率保持不变,滑移按直线变化,表明构件处于弹性阶段受力,抗剪刚度保持不变;②弹塑性阶段:当0.5 P u<P≤0.8P u时,PCSS剪力钉荷载-滑移曲线斜率不断减小,表明构件处于弹塑性阶段受力,抗剪刚度减小;③破坏阶段:当P>0.8P u时,曲线变化平缓,构件在荷载作用下界面上产生了较大的滑移,加速构件破坏,直到栓钉剪断,试验停止。当大、小构件进行力学性能比较时,小构件的受力性能较大构件好,但是实际情况中PCSS剪力连接件多表现为大比例构件形式,大构件考虑尺寸效应和群钉效应影响因素更能模拟出栓钉的实际受力状态。并依据现有剪力钉计算方法,推荐了PCSS剪力钉的适用极限承载力计算公式。

In order to explore the mechanical properties of PCSS,large-scale PCSS shear connection members were designed and tested.The test results show that large-scale PCSS shear connectors are stressed in three stages.①In the elastic stage:0<P≤0.5 P u,the slope of load-slip curve of PCSS shear studs remains unchanged and the slip changes in a straight line,which indicates that the member is in the elastic phase of stress and the shear stiffness remains unchanged.②In elastic-plastic stage:0.5 P u<P≤0.8P u,the slope of the load-slip curve of the PCSS shear studs is continuously decreasing,which indicates that the member is in the elastoplastic stage of stress and the shear stiffness is reduced.③In destruction stage:P>0.8P u,the curve changes smoothly,which indicates that the interface of the component has a large slip under the action of load,which accelerates the failure of the component until the bolt is cut off and the test stops.When the mechanical properties of large and small components are compared,the mechanical properties of the small components are better.However,in practical cases,the PCSS shear connectors are mostly in the form of large-scale components.The actual stress state of studs can be better simulated by considering the influence factors of the size effect and group nail effect of large members.According to the existing calculation method of shear studs,the calculation formula of the applicable ultimate bearing capacity of the PCSS shear studs is recommended.