刘决丁, 范向前, 叶宇霄, 葛菲. 基于解析方法的FRP增强混凝土梁失稳前断裂过程分析[J]. 工程力学, 2023, 40(10): 129-140. DOI: 10.6052/j.issn.1000-4750.2022.01.0081
引用本文: 刘决丁, 范向前, 叶宇霄, 葛菲. 基于解析方法的FRP增强混凝土梁失稳前断裂过程分析[J]. 工程力学, 2023, 40(10): 129-140. DOI: 10.6052/j.issn.1000-4750.2022.01.0081
LIU Jue-ding, FAN Xiang-qian, YE Yu-xiao, GE Fei. FRACTURE PROCESS ANALYSIS OF FRP REINFORCED CONCRETE BEAMS BEFORE INSTABILITY BASED ON ANALYTICAL METHOD[J]. Engineering Mechanics, 2023, 40(10): 129-140. DOI: 10.6052/j.issn.1000-4750.2022.01.0081
Citation: LIU Jue-ding, FAN Xiang-qian, YE Yu-xiao, GE Fei. FRACTURE PROCESS ANALYSIS OF FRP REINFORCED CONCRETE BEAMS BEFORE INSTABILITY BASED ON ANALYTICAL METHOD[J]. Engineering Mechanics, 2023, 40(10): 129-140. DOI: 10.6052/j.issn.1000-4750.2022.01.0081

基于解析方法的FRP增强混凝土梁失稳前断裂过程分析

FRACTURE PROCESS ANALYSIS OF FRP REINFORCED CONCRETE BEAMS BEFORE INSTABILITY BASED ON ANALYTICAL METHOD

  • 摘要: 为研究FRP增强混凝土梁失稳前断裂过程,该文基于混凝土断裂力学理论和非线性FRP-混凝土界面粘结滑移规律,建立了一个跨中裂缝导致界面脱粘的粘聚区模型,采用解析方法推导了FRP增强混凝土梁界面剪切应力、FRP拉应力以及失稳前断裂韧度的公式,为分析FRP-混凝土界面脱粘提供了一种有效的方法,并开展了动态荷载下4种不同初始缝高比(0.2、0.3、0.4和0.5)的FRP增强混凝土梁三点弯曲试验。结果表明,FRP增强混凝土梁的起裂荷载和阻裂荷载随着初始缝高比的增大而逐渐减小,但初始缝高比为0.4时,试件起裂最晚;起裂韧度和阻裂韧度不随初始缝高比的变化而变化,表现出与其他文献类似的规律,验证了断裂韧度解析解的正确性。

     

    Abstract: To study the fracture process of FRP reinforced concrete beam before instability, a cohesive zone model for interfacial debonding due to mid-span crack was established based on the theory of concrete fracture mechanics and the bond-slip law of non-linear FRP-concrete interface. The formulas of interfacial shear stress, FRP tensile stress and fracture toughness before instability of FRP reinforced concrete beams were deduced by analytical method, providing an effective method for analyzing FRP-concrete interface debonding. Three-point bending experiments of FRP reinforced concrete beams with four different initial crack-depth ratios (0.2, 0.3, 0.4 and 0.5) under dynamic load were carried out. The experimental results show that, the crack initiation load and crack resistance load of FRP reinforced concrete beams decrease with the increase of initial crack-depth ratio. When the initial crack-depth ratio is 0.4, the crack initiation of specimens is the latest. The crack initiation toughness and the crack resistance toughness do not change with the change of the initial crack-depth ratio, which is consistent with the observations of other references and verifies the correctness of the analytical solution for fracture toughness.

     

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