欧阳煜, 卞海涛, 杨峥. FRP布加固具有中心裂纹板条的断裂疲劳性能[J]. 工程力学, 2015, 32(3): 158-166. DOI: 10.6052/j.issn.1000-4750.2013.10.0913
引用本文: 欧阳煜, 卞海涛, 杨峥. FRP布加固具有中心裂纹板条的断裂疲劳性能[J]. 工程力学, 2015, 32(3): 158-166. DOI: 10.6052/j.issn.1000-4750.2013.10.0913
OUYANG Yu, BIAN Hai-tao, YANG Zheng. FRACTURE AND FATIGUE BEHAVIOR OF LATH WITH A CENTER CRACK STRENGTHENED WITH FRP SHEET[J]. Engineering Mechanics, 2015, 32(3): 158-166. DOI: 10.6052/j.issn.1000-4750.2013.10.0913
Citation: OUYANG Yu, BIAN Hai-tao, YANG Zheng. FRACTURE AND FATIGUE BEHAVIOR OF LATH WITH A CENTER CRACK STRENGTHENED WITH FRP SHEET[J]. Engineering Mechanics, 2015, 32(3): 158-166. DOI: 10.6052/j.issn.1000-4750.2013.10.0913

FRP布加固具有中心裂纹板条的断裂疲劳性能

FRACTURE AND FATIGUE BEHAVIOR OF LATH WITH A CENTER CRACK STRENGTHENED WITH FRP SHEET

  • 摘要: 研究了FRP布加固具有中心穿透裂纹板条在两端拉伸载荷作用下的断裂和疲劳,得到了FRP布加固板条的界面剪应力,利用叠加原理和断裂力学的基本结果,推导了FRP加固板条裂纹尖端的应力强度因子解析表达式。在此基础上,分别给出了FRP加固具有中心穿透裂纹板条Paris和Elber模型的疲劳寿命预测公式,通过实例计算发现,循环荷载作用下FRP加固具有中心穿透裂纹板条的裂纹闭合效应非常显著,应采用Elber模型预测其疲劳寿命,而对于未加固的裂纹板条,应采用Paris模型预测其疲劳寿命。同时,参数分析表明:FRP布加固长度存在最优值,且FRP刚度对应力强度因子幅值影响显著,应力强度因子幅值随着FRP刚度的增加而减小,因此,其疲劳寿命延长。

     

    Abstract: Fracture and fatigue of a lath with a center crack strengthened with FRP sheet, subject to tensile loads at its two ends, was investigated, and the interfacial shear stress of the FRP-strengthened lath was obtained. Based on the superposition principle and the fracture mechanics, an analytical expression of the stress intensity factor at crack tip of the FRP-strengthened lath was derived. Then, the formulas of the fatigue life assessment of the FRP-strengthened lath with a center crack were presented with the Paris model and Elber model, respectively. From analysis of a numerical example, it was found that the effect of the crack closure is significant for the FRP-strengthened lath with a center crack under cyclic loading, and the Elber model should be employed to assess its fatigue life, while Paris model should be employed to assess fatigue life of the un-strengthened lath. Furthermore, the parameter study showed that there exists an optimal length of the FRP sheet, and the influence of the FRP stiffness on the amplitude of the stress intensity factor is significant. The amplitude of the stress intensity factor decreases when the FRP stiffness increases, resulting in an increased fatigue life.

     

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