【摘要】 为分析纤维增强塑料筋-纤维混凝土梁抗剪承载力，同时为该情形下的工程设计提供理论指导，对现有试验进行模拟并重新设计影响因素及其水平。采用ABAQUS/Explicit对22根梁进行准静态四点弯曲细观模拟，并对梁的荷载-跨中挠度关系以及破坏形态进行讨论。研究了剪跨比(1.5、2.5)、混凝土抗压强度(27、54、81 MPa)、纤维体积掺量(0、0.75%、1.50%)，以及同长径比下玄武岩和聚丙烯纤维对抗剪性能的影响。研究结果表明：在剪切破坏的情形下，钢纤维体积掺量对梁的抗剪承载力和破坏形态有显著影响，且该效应随着混凝土抗压强度的改变而变化。在混凝土抗压强度较低时，梁的破坏形态由斜拉破坏改变为由混凝土压碎而导致的弯曲破坏。同时，在纤维与基体完全黏结的情形下，纤维的变形能力越强，增加纤维体积掺量对梁破坏形态和承载力的影响越不显著。更多还原

【Abstract】 To analyze the shear capacity of fiber-reinforced polymer(FRP) bar-reinforced fiber concrete beams and provide theoretical guidance for engineering design under such conditions, existing experiments are simulated and influencing factors and their levels are redesigned. Quasi-static four-point bending meso-scale simulations are conducted on 22 beams using ABAQUS/Explicit. Then the load-midspan deflection relationship and failure modes of the beams are discussed. The effects of shear span ratio(1.5, 2.5), concrete compressive strength(27, 54, 81 MPa), fiber volume fraction(0, 0.75%, 1.50%), and the type of fiber(basalt and polypropylene fibers with the same length-to-diameter ratio) on the shear performance are investigated. The results indicate that under shear failure, the steel fiber volume fraction significantly affects the shear capacity and failure mode of the beams, and this effect varies with the change in concrete compressive strength. When the concrete compressive strength is low, the failure mode of the beams changes from diagonal tension failure to flexural failure caused by concrete crushing. Meanwhile, when fibers are fully bonded to the matrix, the greater the deformability of the fibers, the less significant the effect of increasing the fiber volume fraction becomes on the failure mode and bearing capacity of the beams.更多还原