部分抗剪连接钢-预制混凝土板组合梁疲劳性能试验研究

Experimental Study on Fatigue Behavior of Steel-precast Concrete Slab Composite Beams with Partial Shear Connection

为了研究部分抗剪连接钢-预制混凝土板组合梁的疲劳性能,对两根组合梁试件分别开展了静力和疲劳加载试验。在疲劳试验中,跨中钢梁母材在200 MPa应力幅作用下经历了95.5万次等幅疲劳加载后最终发生了疲劳断裂;组合梁试件在疲劳荷载作用下产生了明显的刚度退化,在经历50万次的疲劳加载后,由疲劳损伤引起的组合梁跨中附加挠度约为初始挠度的45.1%。结果表明:焊缝缺陷是焊接钢梁发生疲劳破坏的重要诱因;部分抗剪连接组合梁在疲劳荷载作用下的附加变形计算应予以重视;通过合理设计,部分抗剪连接钢-预制混凝土板组合梁具有应用于桥梁工程的可行性。

To investigate the fatigue performance of steel-precast concrete slab composite beams with partial shear connection,two composite beams were tested under static and fatigue loading respectively.Fatigue fracture occurred after the mother metal of steel girder at the mid-span was subjected to 955 000 loading cycles with stress range of 200 MPa in the fatigue test.The stiffness of the composite beam degenerated significantly due to fatigue loading,and the additional deflection caused by fatigue damage at the mid-span of the composite beam is about 45.1percent of the initial deflection after 500 000 loading cycles.The experimental results indicate that weld flaw is the important inducement for the fatigue failure of the welded girder.More attention should be paid to the additional deformation calculation of composite beams with partial shear connection subjected to fatigue load.It is feasible for steel-precast concrete slab composite beams with partial shear connection which are properly designed to be applied in bridge engineering.