Investigation of sub-critical fatigue crack growth in FRP/concrete cohesive interface using digital image analysis
Investigation of sub-critical fatigue crack growth in FRP/concrete cohesive interface using digital image analysis
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DOI：
10.1016/j.compositesb.2013.02.015
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发表时间：
2013-08-01
影响因子：
13.1
通讯作者：
Subramaniam, Kolluru V.
中科院分区：
文献类型：
--
作者：
Carloni, Christian;Subramaniam, Kolluru V.
采用直剪试验装置，研究了疲劳荷载作用下FRP与混凝土脱粘过程中亚临界裂纹扩展过程中的内聚应力传递。研究重点是高振幅/低周疲劳。疲劳亚临界裂纹扩展发生在小于单调准静态加载获得的界面静态结合能力的载荷下，并且与较小的界面断裂能值相关。利用数字图像相关技术获得了剥离过程中的应变分布。结果表明：在单调准静态载荷作用下，FRP在疲劳过程中的应变分布与剥离过程中的应变分布相似；间接证明了准静态单调加载所采用的内聚裂纹模型和应变分布形状能够充分描述疲劳加载过程中的应力传递。在准静态单调加载下，疲劳过程中应力传递区长度小于界面裂纹内聚区长度。在疲劳加载过程中，FRP片材的应变分布不受疲劳加载的影响。提出了一种预测疲劳过程中脱粘裂纹扩展的新公式。(c) 2013 Elsevier Ltd.版权所有。
The cohesive stress transfer during the sub-critical crack growth associated with the debonding of FRP from concrete under fatigue loading is experimentally investigated using the direct shear test set-up. The study focused on high-amplitude/low-cycle fatigue. The fatigue sub-critical crack growth occurs at a load that is smaller than the static bond capacity of the interface, obtained from monotonic quasi-static loading, and is also associated with a smaller value of the interfacial fracture energy. The strain distribution during debonding is obtained using digital image correlation. The results indicate that the strain distribution along the FRP during fatigue is similar to the strain distribution during debonding under monotonic quasi-static loading. The cohesive crack model and the shape of the strain distribution adopted for quasi-static monotonic loading is indirectly proven to be adequate to describe the stress transfer during fatigue loading. The length of the stress transfer zone during fatigue is observed to be smaller than the cohesive zone of the interfacial crack under quasi-static monotonic loading. The strain distribution across the width of the FRP sheet is not altered during and by fatigue loading. A new formulation to predict the debonding crack growth during fatigue is proposed. (c) 2013 Elsevier Ltd. All rights reserved.