预应力复合材料模壳-混凝土组合桥面板疲劳性能

Fatigue behavior of composite bridge deck with prestressed FRP shell and concrete

针对一种新型预应力纤维增强复合材料(FRP)模壳-混凝土组合桥面板,研究了该组合桥面板在变化应力水平下的疲劳性能。试验针对疲劳破坏形态、应力状态、界面形态和疲劳寿命等因素进行了系统研究。结果表明:组合桥面板疲劳破坏主要由于受压区混凝土压碎控制、部分构件发生复材模壳局部疲劳撕裂,并且组合桥面板中预应力板条在疲劳荷载下保持良好性能。组合桥面板在发生疲劳破坏后,均保持较高的残余强度,为结构提供安全储备。通过数据拟合得到组合桥面板的荷载水平-疲劳寿命(S-N)曲线,可预测在不同荷载下的疲劳寿命。

Focusing on a novel FRP-RC composite bridge deck,the fatigue behavior of the composite bridge decks under varying loading level were studied in this paper. Fatigue failure modes,stress status,interface and fatigue life were studied. The results show that the fatigue failure of the composite bridge deck is determined by the concrete crushing in the compression zone and partially by FRP shell tearing.FRP prestressed laminates in the shell show a good fatigue performance without occurring significant fatigue damages.The composite bridge decks exhibit a high residual strength after fatigue loading providing safety stock for structures. The proposed fatigue S-N curve of the composite bridge deck can predict the fatigue life of the composite deck under different loads.