Abstract: Crane metal constructions under long-term alternating loads were easy to produce fatigue cracks， a combination of CFRP and stop-hole was studied to rapair the cracks herein. Firstly， the finite element models of stop-hole， CFRP and composite repair were established， and the stress-strain states and stress concentration factors were analyzed. Then， the finite element model of composite repair with the stop-hole missing crack tips was built to study the effects of CFRP reinforcement on the repair of stop-hole. Finally， the effectiveness of composite repair for damaged members was studied by static tensile strength tests， the feasibility of this technology was verified through comparing the testing and simulation results. The results show that the composite repair method may eliminate the singularity of the crack tips， reduce the nominal stresses， improve the bearing capacities of the specimens， and make up for the weld cracks inadequacy of drilling stop holes， which provides an reference for engineering maintenances.

Key words: carbon fiber reinforced polymer （CFRP）, stop-hole, composite repair, singularity, nominal stress, bearing capacity

摘要： 针对起重机金属结构在长期疲劳交变载荷作用下易产生疲劳裂纹的问题，采用碳纤维复合材料（CFRP）加固止裂孔的方法对裂纹进行复合修复。建立不同载荷下止裂孔、CFRP以及复合修复的有限元模型，分析计算应力应变状态和应力集中系数；建立止裂孔打偏情况下复合修复的有限元模型，研究CFRP加固对止裂孔修复的影响；通过静拉伸强度试验，研究复合修复方法对损伤构件的修复效果，并与仿真结果进行对比，验证了CFRP与止裂孔复合修复这一技术的可行性。结果表明，复合修复方法相比于止裂孔及CFRP修复效果，不仅可以消除裂纹尖端的奇异性，减小名义应力，提高试件的承载能力，还可以弥补钻止裂孔修复焊缝裂纹的不足，为工程维修提供了参考。

关键词: 碳纤维复合材料, 止裂孔, 复合修复, 奇异性, 名义应力, 承载能力