首页|基于CFRP布和SMA/CFRP组合贴片的桥梁横隔板疲劳裂纹修复方法

基于CFRP布和SMA/CFRP组合贴片的桥梁横隔板疲劳裂纹修复方法

Repair methods for fatigue cracks in bridge diaphragms based on CFRP sheets and SMA/CFRP composite patches

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为了解决长期服役状态下正交异性钢桥面板的横隔板弧形切口处在车致振动和反复轮压荷载作用下的疲劳开裂问题,提出了 2种加固方法,即碳纤维增强复合材料(CFRP)布粘贴止裂孔法和通过激活形状记忆合金(SMA)引入预应力的SMA/CFRP组合贴片粘贴止裂孔法;对修复后的横隔板试件进行静力和疲劳加载试验,建立了相应的有限元模型对不同加固方法进行数值模拟和参数分析,对比了不同加固方法的修复效果.研究结果表明:在止裂孔的基础上粘贴CFRP布和SMA/CFRP组合贴片后,横隔板止裂孔边的应力相比单纯止裂孔修复时分别降低了 12.46％和44.90％,横隔板的疲劳寿命分别为单纯止裂孔修复横隔板的2.57和5.07倍,2种方法可有效提高开裂区域的局部刚度,改善横隔板开裂局部的应力集中和疲劳受力性能;采用CFRP布粘贴修复时,增加CFRP布层数可以明显降低横隔板上的应力水平和应力集中程度,但为保证CFRP布和钢板间的黏结性能,实际应用中建议粘贴2～3层CFRP布为宜;采用SMA/CFRP组合贴片修复时,钢板上的应力集中程度随SMA丝激活应力的增加近似成线性下降,实际工程中可通过增大SMA丝的激活应力来有效提升修复效果.
In order to solve the fatigue cracking problem of the diaphragm arc-shape cutouts in the orthotropic steel bridge decks due to vehicle-induced vibration and cyclical wheel load under prolonged service conditions,two kinds of reinforcement methods,including carbon fiber reinforced polymer(CFRP)sheets covering crack-stop holes method and shape memory alloys(SMA)/CFRP composite patches covering crack-stop holes method which introduced prestress by activating SMA were proposed.The static and fatigue loading tests were carried out on the repaired diaphragm specimens,the corresponding finite element models were established for numerical simulation and parameter analysis of different reinforcement methods,and the repair effects of different reinforcement methods were compared.Research results show that,after bonding CFRP sheets and SMA/CFRP composite patches on the basis of crack-stop holes,the stresses at the hole edges of diaphragms reduce by 12.46％and 44.90％,respectively,and the fatigue lives of diaphragms repaired with CFRP sheets and SMA/CFRP composite patches are 2.57 and 5.07 times that of diaphragms repaired simply with the crack-stop holes,respectively.Both the two methods can effectively improve the local stiffnesses of the cracked region,and alleviate the stress concentration and improve the fatigue performance of the cracked diaphragms.When repairing with CFRP sheets,increasing the number of CFRP sheets layers can significantly reduce the stress and stress concentration on the diaphragm.To guarantee the bonding performance between CFRP sheets and steel plates,however,it is appropriate to apply 2-3 layers of CFRP sheets in practical applications.When repairing with SMA/CFRP composite patches,the stress concentration on steel plates exhibits an approximately linear decreasing trend with the increase of SMA wire actived stress.Consequently,the repair effect can be effectively enhanced by increasing the SMA wire actived stress in practical engineering.7 tabs,21 figs,30 refs.

bridge engineeringcrack of diaphragmfinite element simulationstructural reinforcementrepair schemeSMA/CFRP compositite patch

强旭红、武亚鹏、姜旭、林志平

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同济大学土木工程学院,上海 200092

福建省高速公路集团有限公司,福建福州 350001

桥梁工程 横隔板裂纹 有限元模拟 结构加固 修复方案 SMA/CFRP组合贴片

国家自然科学基金项目国家自然科学基金项目国家重点研发计划重庆市自然科学基金项目中央高校基本科研业务费专项资金项目

52278206522782072020YFD1100403CSTB2022NSCQ-MSX121922120210577

2024

10.19818/j.cnki.1671-1637.2024.01.011

交通运输工程学报
长安大学

交通运输工程学报

CSTPCD北大核心
影响因子：1.306
ISSN：1671-1637
年,卷(期)：2024.24(1)
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