基于断裂力学的CFRP加固桥梁疲劳裂纹扩展研究

发布时间：2018-02-23 23:28

  本文关键词： 桥梁工程 碳纤维布 断裂力学 疲劳 应力强度因子　出处：《中国公路学报》2014年11期 　论文类型：期刊论文

【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。
[Abstract]:On the basis of the assumption of linear progressive superposition, the fatigue crack growth rate of reinforced concrete bridge strengthened by CFRP is theoretically analyzed. On the basis of the expression of crack propagation model, the fatigue crack growth rate of reinforced concrete bridge strengthened by CFRP is theoretically analyzed. By analyzing the relationship between stress intensity factor and equivalent crack length of three-point bending beam, the crack propagation rate is obtained, and the fatigue life of bridge strengthened by CFRP is studied in advance. At the same time, the fatigue crack growth test of bridge strengthened by CFRP is carried out, and the strain accumulation analysis of single and double layer CFRP strengthened test beams along the direction of the length of the bridge is carried out. The crack growth rate and propagation behavior of strengthened beams under fatigue load are described. The results show that CFRP can give full play to the fatigue resistance of strengthened beams under fatigue load. According to the comparison between the theoretical calculation results and the experimental results, the theoretical calculation method for the fatigue life estimation of reinforced concrete bridges strengthened with CFRP has a small error, which meets the actual needs.
【作者单位】： 东北大学资源与土木工程学院;辽宁交通规划设计院;
【基金】：国家自然科学基金重大项目(90915005)
【分类号】：U441.4;U445.72
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本文编号：1528023