基于单层纤维失效准则的FRP型材-混凝土组合梁极限承载力计算与试验

Calculation and experiments on ultimate bearing capacity of FRP-concrete composite beams based on single layer failure criteria

为研究FRP型材-混凝土组合的梁失效模式与承载能力,提出了一种基于单层纤维失效准则的组合梁极限承载力计算方法.首先,分析了FRP材料特性、铺设方式、界面连接等对组合梁结构性能的影响,揭示了FRP型材-混凝土组合梁失效模式多样性的规律.然后,基于FRP型材失效和混凝土桥面板失效,将各类破坏模式归纳为2类.最后,采用细观力学方法,建立了各单层纤维所承受的应力计算公式.针对3片FRP型材-混凝土组合梁,进行了单调荷载作用下的破坏性试验.试验结果表明,承载能力计算结果与试验结果吻合较好.所提方法可较为准确地判定组合梁失效模式,简化了FRP型材-混凝土组合梁的计算复杂度,适用于由FRP纤维破坏引起的结构失效.

In order to study the failure mode and bearing capacity of fiber reinforced polymer （FRP） -concrete composite beams, a calculation method for the ultimate bearing capacity of composite beams based on the single layer failure criteria was proposed. First, the effects of material properties, laying ways, and interface connection ways on the structural behaviors of FRP-concrete composite beams were analyzed. The rule of diversity failure modes of FRP-concrete composite beam was revealed. Then, a variety of types of damage were simply classified into two categories based on FRP failure and concrete deck destruction. Finally, the formulas to calculate stress of each FRP lamina were established by micromechanics methods. Destructive tests of three pieces of FPR-concrete composite beams subjected to monotonic load were conducted. The calculation results agree well with the experimental results. The proposed calculation method can judge the failure mode of com- posite beams and simplify the computational complexity. Therefore, it is applicable to structural failure caused by destruction of FRP fiber.