基于断裂力学的CFRP加固桥梁疲劳裂纹扩展研究  

Study on Fatigue Crack Propagation of CFRP Reinforced Bridge Based on Fracture Mechanics

作　　者：李明[1] 朱浮声[1] 赵云鹏 

机构地区：[1]东北大学资源与土木工程学院,辽宁沈阳110004 [2]辽宁交通规划设计院,辽宁沈阳110179

出　　处：《中国公路学报》2014年第11期63-68,共6页China Journal of Highway and Transport

基　　金：国家自然科学基金重大项目(90915005)

摘　　要：在线性渐进叠加假定的基础上,对碳纤维增强复合材料(CFRP)加固钢筋混凝土桥梁的疲劳裂纹扩展速率进行理论分析,在裂纹扩展模型表达式的基础上,通过分析三点弯曲梁应力强度因子与等效裂缝长度之间的关系,求得裂纹扩展速率,进而对CFRP加固桥梁的疲劳寿命进行预估算研究;同时进行了CFRP加固桥梁疲劳裂纹扩展试验研究,通过单、双层CFRP加固试验梁沿布长方向的应变累积分析,阐述了荷载作用下加固梁裂纹扩展速率和扩展行为。结果表明:加固梁在疲劳荷载作用下,CFRP充分发挥了其抗疲劳特性;从理论计算结果与试验值对比情况看,CFRP加固钢筋混凝土桥梁疲劳寿命估算理论计算方法误差较小,满足实际需求。Theoretical analysis of CFRP reinforced concrete bridge fatigue crack propagation rate was conducted on the basis of linear progressive superimposed assumption.On the basis of crack propagation model expression and the analysis of the relationship between the three point bending beam stress intensity factor and the equivalent crack length,the crack growth rate was calculated to estimate the fatigue life of CFRP reinforced bridge.At the same time,experiment study was made on the fatigue crack propagation of the CFRP reinforced bridge,and the strain accumulation of the reinforced beams by single and double CFRP layer along the CFRP direction was analyzed to expound the growth rate and propagation behavior of the reinforced beam crack under load.The results show that CFRP plays an important role in the anti-fatigue for reinforced beam under fatigue load.The fatigue life estimation theory is proved to have smaller error which meets the actual demand of the CFRP reinforced concrete bridge through comparing theoretical calculation results with the test results.

关 键 词：桥梁工程 碳纤维布 断裂力学 疲劳 应力强度因子 

分 类 号：U445.72[建筑科学—桥梁与隧道工程]