摘要
针对钢桥中钢板疲劳裂纹进行了一系列疲劳裂纹修复试验研究,以确定不同修复方法下结构的疲劳性能。高弹模CFRP(碳纤维增强复合材料)修复法是通过粘贴高弹模CFRP布来增大结构刚度,以延长结构疲劳寿命,且碳纤维材料基本不会产生疲劳裂纹,具有较好的抗疲劳效果。采用数值模拟和试验研究相结合的方法,首先对修复钢板的应力分布和特点进行了详细的分析,然后通过3组对比疲劳试验,确定了不同修复方法对损伤钢板疲劳寿命的增强效果。最后利用修复试验值与各国规范规定的S-N曲线进行比较,分析已修复钢板的疲劳性能。研究结果表明:在止裂孔上覆盖粘贴高弹模CFRP布可有效减小孔边应力集中,具有延长结果疲劳寿命的效果,修复后的裂纹钢板的疲劳寿命是仅用止裂孔修复的裂纹钢板疲劳寿命的8倍以上。仅用止裂孔法修复损伤钢板不足以满足各国规范规定的疲劳强度要求,而在止裂孔法上进一步采用高弹模CFRP布修复后的损伤钢板的抗疲劳性能更优,其疲劳强度等级高于美国规范AASHTO中的A类细节等级。
In order to repair fatigue cracks of steel plates in steel bridges,a series of fatigue crack repair tests of steel plates are carried out to determine the fatigue performance of structures using different repair methods.The high modulus carbon fiber reinforced polymer(CFRP)repair method is to increase the structural stiffness by pasting high modulus CFRP strips,which can also prolong the fatigue life of the structures.Carbon fiber has an excellent anti-fatigue performance,and fatigue cracks will hardly occur.In this paper,the finite element method and experimental research method are combined to analyze the stress distribution and characteristics of the repaired steel plates.Then three sets of comparative fatigue tests are conducted to determine the enhancement effect of different repair methods on fatigue life of the damaged steel plates.Finally,the fatigue performance of the repaired steel plates is compared with the S-N curves of national standards by using the repair test values.The research result shows that covering and pasting the high elastic modulus CFRP strips on the stopping hole can effectively reduce the stress concentration on the hole edge.Comparing with the cracked steel plates strengthened only with stopping hole,the application of CFRP strips can prolong the fatigue life by more than 8 times.The method repairing the damaged steel plates with stopping hole is not enough to meet the fatigue strength requirements of various countries.But the damaged steel plates after further repairing with CFRP strips have better fatigue resistance,and the fatigue strength level is higher than the Category A of AASHTO.
作者
吕志林
姜旭
强旭红
罗程巍
张建东
LYU Zhilin;JIANG Xu;QIANG Xuhong;LUO Chengwei;ZHANG Jiandong(College of Civil Engineering,Tongji University,Shanghai 200092,China;Jiangsu Transportation Institute Co.,Ltd.,Nanjing 210019,China)
出处
《建筑钢结构进展》
CSCD
北大核心
2022年第5期92-100,共9页
Progress in Steel Building Structures
基金
国家自然科学基金(51408424)
广东省重点领域研发计划“现代工程技术”重点专项(2019B111106002)。
关键词
钢桥
钢板
高弹模CFRP
疲劳裂纹
修复
steel bridge
steel plate
high elastic modulus CFRP
fatigue crack
repair
