基于CFRP和SMA修复钢桥横隔板疲劳裂纹的方法研究与应用  

Research and application of repairing method for fatigue cracks in steel bridge diaphragm employing CFRP and SMA

作　　者：强旭红[1] 武亚鹏 姜旭[1] 刘勇 QIANG Xuhong;WU Yapeng;JIANG Xu;LIU Yong(College of Civil Engineering,Tongji University,Shanghai 200092,China;Jiangsu Sutong Bridge Co.,Ltd,Nantong 226001,China)

机构地区：[1]同济大学土木工程学院,上海200092 [2]江苏苏通大桥有限公司,江苏南通226001

出　　处：《建筑结构学报》2024年第8期129-140,共12页Journal of Building Structures

基　　金：国家自然科学基金项目(52278206,52278207);国家重点研发计划重点专项(2020YFD1100400);上海市自然科学基金资助项目(21ZR1466100)。

摘　　要：针对正交异性钢桥面板横隔板弧形切口处疲劳裂纹,在传统止裂孔法的基础上,提出粘贴碳纤维增强复合(carbon fiber reinforced polymer,CFRP)布、形状记忆合金(shape memory alloys,SMA)/CFRP组合贴片和铁基形状记忆合金(Fe-SMA)板对其进行加固修复,并对采用不同修复方法的8个含裂纹的横隔板进行疲劳加载试验。结果表明:粘贴CFRP布、SMA/CFRP组合贴片和Fe-SMA板均可有效提高横隔板开裂局部的刚度,激活SMA可进一步引入预压应力,从而明显改善开裂区域的应力集中、延缓疲劳裂纹的萌生和扩展,显著提高横隔板的疲劳寿命;粘贴CFRP布和SMA/CFRP组合贴片修复横隔板的疲劳寿命分别为单纯止裂孔修复横隔板的2.59倍和5.10倍,粘贴Fe-SMA板修复横隔板的疲劳寿命显著提高,其疲劳寿命为单纯止裂孔修复横隔板的12.68倍。通过对苏通大桥与其他千米级大跨度钢桥横隔板疲劳裂纹的实桥修复应用,验证了采用Fe-SMA板粘贴止裂孔法的实操可行性和有效性。To repair cracks at the arc-shape cutouts of the diaphragm in steel bridges,reinforcement methods of bonding CFRP sheets,SMA/CFRP composite patches,and Fe-SMA plates were proposed based on the traditional crack-stop hole method.The fatigue tests were conducted on eight cracked diaphragm specimens with different repair methods.The results show that bonding CFRP sheets,SMA/CFRP composite patches,and Fe-SMA plates can effectively improve the stiffness of the cracked region and introduce precompression by activating SMA,thereby reducing the stress concentration,delaying the crack initiation and propagation,thus significantly improving the fatigue life.The fatigue life of diaphragms repaired by CFRP sheets and SMA/CFRP composite patches are 2.59 and 5.10 times that of the diaphragm repaired solely by crack-stop holes,respectively.Moreover,the diaphragm repaired by Fe-SMA plates exhibits a remarkable enhancement,where the resulting fatigue life is 12.68 times that of the diaphragm repaired using crack-stop holes.Furthermore,the feasibility and effectiveness of Fe-SMA plates covering crack-stop holes method were verified through actual repair applications of cracked diaphragm cutouts in the Sutong Bridge and other kilometer-level steel bridges.

关 键 词：结构加固 横隔板裂纹 铁基形状记忆合金 疲劳试验 修复效果 

分 类 号：TU391[建筑科学—结构工程] TU392TU317.1