CFRP布加固具有边缘裂纹板条的疲劳性能  

Fracture and Fatigue Behaviour of Plate Strip with Edge Cracks Strengthened with CFRP Sheet

作　　者：杨峥[1] 于波[2] 敖耀东 杨骁[1] 

机构地区：[1]上海大学土木工程系,上海200072 [2]中国建筑第二工程局有限公司(沪),上海200135

出　　处：《力学季刊》2014年第3期408-418,共11页Chinese Quarterly of Mechanics

基　　金：国家高技术研究发展计划资助项目(2009AA032303-2)

摘　　要：将碳纤维增强复合材料(CFRP)布在板条两表面双面粘贴加固具有边缘穿透裂纹的板条,研究了加固板条在两端循环拉伸载荷作用下的断裂和疲劳性能.首先建立了CFRP布加固板条粘结层与CFRP布/板条的界面剪应力控制方程,并求得两端均布拉力作用下CFRP布加固具有边缘穿透裂纹的板条的界面剪应力解析解.其次,利用叠加原理推导了CFRP加固板条裂纹尖端的应力强度因子表达式,分别给出了其Paris和Elber模型疲劳寿命公式,通过与相关实验结果的比较,发现Elber模型的疲劳寿命公式与试验结果较吻合.最后的参数研究表明:CFRP布刚度对应力强度因子范围有显著的影响,且应力强度因子范围随CFRP布长度或粘贴层剪切模量的增加而减小,并趋于定值.同时,粘贴胶厚度对应力强度因子范围几乎没有影响.The plate strip with through edge cracks was strengthened with Carbon Fiber Reinforced Polymer （CFRP） sheets by bonding them on plate strip＇s two surfaces, and its behavior of fracture and fatigue behavior under cycle tensile loads at its two ends was investigated. First, the governing equation of the interfacial shear stress between the adhesive layer and CFRP sheet/plate strip of the CFRP-strengthened plate strip was established, and the analytical solution of the interfacial shear stress of the CFRP-strengthened plate strip subjected to uniform loads at its two ends was obtained. Then, based on the superposition principle, an expression of the stress intensity factor at the crack tip of the CFRP-strengthened plate strip was derived, and the formulas of the fatigue life of the CFRP-strengthened plate strip with through edge cracks were presented based on the Paris model and Elber model, respectively. By comparing the formula resuRs with the experimental ones, it is revealed that the results of the fatigue life formula of the Elber model are more agreement with the experimental ones. Finally, the parameter study shows that the influence of the stiffness of the CFRP sheet on the range of the stress intensity factor is remarkable, and the range of the stress intensity factor decreases with the increases of the length of the CFRP sheet or shear modulus of the adhesive layer and converges to a constant value. Furthermore, the thickness of the adhesive layer has little effect on the range of the stress intensity factor.

关 键 词：FRP加固 叠加原理 应力强度因子 疲劳寿命 参数分析 

分 类 号：O346[理学—固体力学] TU973.254[理学—力学]