摘要
横隔板弧形切口疲劳开裂为正交异性钢桥面板的主要疲劳病害之一。为研究该部位的疲劳性能,分析碳纤维增强复合材料(carbon fiber reinforced polymer,CFRP)参数对加固效果的影响,首先,建立钢梁节段模型,在弧形切口应力幅最大处引入初始裂纹,基于断裂力学理论得到疲劳荷载作用下横隔板弧形切口处的开裂模式及疲劳寿命;然后,建立CFRP板加固模型,改变各加固参数,对比不同初始裂纹条件下裂纹扩展过程中的应力强度因子变化规律,探究CFRP板长度、宽度、厚度、弹性模量以及胶层剪切模量等参数对加固效果的影响;最后,给出推荐加固参数组合。研究结果表明:横隔板弧形切口处疲劳裂纹为I型裂纹,疲劳寿命约为576.42万次;CFRP板加固能有效降低裂纹尖端应力强度因子幅值,但是CFRP板长度与宽度存在加固的临界尺寸,当尺寸大于这一临界值时,其对加固效果影响极小;CFRP板厚度、胶层剪切模量对加固效果的影响随参数增大而逐渐减弱;采用长×宽×厚为45.0 mm×30.0 mm×2.0 mm、弹性模量为460 GPa的CFRP板进行加固后,裂纹将不再扩展,疲劳寿命显著提高。
Fatigue cracking at the diaphragm cutout is one of the major diseases of orthotropic steel decks(OSDs).To investigate the influence of fatigue performance at this location and analyze the strengthening effect of the parameters of Carbon Fiber Reinforced Polymer composite materials,firstly,a segment model of the steel beam was established,and an initial crack was introduced at the maximum stress amplitude of the curved incision.Based on fracture mechanics theory, the cracking mode and fatigue life of the curved incision in the transverse diaphragm under fatigue load were obtained. Secondly, a strengthening model of CFRP plate was established, the reinforcement parameters were changed, and the change law of stress intensity factor in the process of crack propagation under different initial crack conditions was compared to explore the influence of CFRP plate length, width, thickness, elastic modulus and shear modulus of adhesive layer on the reinforcement effect. Finally, a recommended combination of reinforcement parameters was given. The results show that the fatigue crack is type I and the fatigue life is about 5.764 2 million times. CFRP reinforcement can effectively reduce the SIF range at crack tip, but there is a critical value for the length and width of CFRP plate. When the size is larger than this value, it has little influence on the reinforcement effect. The influence of the thickness of CFRP plate and the shear modulus of the adhesive layer on the reinforcement effect gradually decreases with the increase of the parameters. After reinforcement with CFRP plates with length × width × thickness of 45.0 mm×30.0 mm×2.0 mm and an elastic modulus of 460 GPa, cracks will no longer expand and the fatigue life will be significantly improved.
作者
宋旭明
罗祥威
季苏瑶
唐冕
SONG Xuming;LUO Xiangwei;JI Suyao;TANG Mian(School of Civil Engineering,Central South University,Changsha 410075,China;Nanjing Metro Resources Development Co.Ltd.,Nanjing 210005,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2024年第3期1046-1055,共10页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(52078486)。
关键词
正交异性钢桥面板
弧形切口
断裂力学
疲劳性能
CFRP加固
参数分析
orthotropic steel bridge panel
diaphragm cutout
fracture mechanics
fatigue performance
CFRP reinforcement
parameter analysis
