首页|腐蚀-疲劳荷载耦合作用下桥梁拉索高强钢丝自漏磁信号变化规律

腐蚀-疲劳荷载耦合作用下桥梁拉索高强钢丝自漏磁信号变化规律

Variation laws of self-magnetic flux leakage signals of high-strength steel wires in bridge cables under coupling effect of corrosion-fatigue loads

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为增强桥梁拉索高强钢丝漏磁检测的实用性,开展了腐蚀、应力单一因素作用试验与预腐蚀-疲劳-腐蚀、预疲劳-腐蚀-疲劳三阶段交互作用试验,阐述了腐蚀-疲劳耦合作用对自漏磁信号的影响机制.研究结果表明:腐蚀区域的自漏磁信号极值随腐蚀时间的增加而增加,且变化特征越发明显,腐蚀缺陷引起的异常自漏磁信号最大变化可达50 000 nT;随着疲劳加载循环次数的增加,无锈蚀高强钢丝自漏磁信号整体呈现先增加后稳定的趋势,当疲劳加载循环次数大于10 000时,磁场强度的增加速率降低且趋于平缓;预腐蚀后施加的交变应力场会削弱腐蚀缺陷引起的自漏磁信号,再次腐蚀后的磁场信号变化与预腐蚀程度有关,预腐蚀9 h后施加疲劳荷载,之后再腐蚀3 h,与单一腐蚀12 h相比,自漏磁信号强度削弱了 32%;施加预疲劳交变应力场可强化磁场,导致腐蚀后自漏磁信号极值增加,当预疲劳加载循环次数从1 000增加至100 000时,自漏磁信号强度增大了 30%.由此可见,早期腐蚀引起的高强钢丝异常自漏磁信号可被疲劳作用掩盖,考虑单一腐蚀与应力变化难以反映高强钢丝自漏磁检测效果,需综合考虑腐蚀-疲劳的耦合效应,以获得桥梁拉索高强钢丝自漏磁信号变化规律,从而为桥梁拉索无损检测提供分析依据.
To enhance the practicality of magnetic flux leakage detection for high-strength steel wires in bridge cables,the corrosion and stress single factor tests,as well as three-stage interaction tests of pre-corrosion-fatigue-corrosion and pre-fatigue-corrosion-fatigue were conducted,and the mechanism for the influence of corrosion-fatigue coupling effect on the self-magnetic flux leakage signal was explained.Research results show that the extreme self-magnetic flux leakage signals in the corrosion area increase with the corrosion time,and the variation characteristics are becoming more and more obvious.The maximum variation in the abnormal self-magnetic flux leakage signals caused by the corrosion defect can reach up to 50 000 nT.As the fatigue loading cycle number increases,the self-magnetic flux leakage signal of non-corroded high-strength steels wire is on an overall increasing trend before getting stabilized.When the fatigue loading cycle number exceeds 10 000,the increasing rate of magnetic field intensity decreases and tends to be stable.The alternating stress field applied after the pre-corrosion weakens the self-magnetic flux leakage signal caused by the corrosion defect,and the variation in the magnetic field signal after the second corrosion is related to the degree of pre-corrosion.Under the fatigue load after the pre-corrosion for 9 h,and then in the second corrosion for 3 h,the strength of the self-magnetic flux leakage signal reduces by 32%compared with that in the single corrosion for 12 h.Applying a pre-fatigue alternating stress field can strengthen the magnetic field,leading to an increase in the extreme self-magnetic flux leakage signal after the corrosion.When the pre-fatigue loading cycle number increases from 1 000 to 100 000,the strength of the self-magnetic flux leakage signal increases by 30%.It follows that the abnormal self-magnetic flux leakage signals of high-strength steel wires caused by the initial corrosion can be masked by the fatigue effect,making it difficult to reflect the detection effect of self-magnetic flux leakage of high-strength steel wires by just considering a single factor of variation in the corrosion or stress.Therefore,it is necessary to comprehensively consider the corrosion-fatigue coupling effect,so as to obtain the variation laws of self-magnetic flux leakage signals of high-strength steel wires in bridge cables,thereby providing an analytical basis for the non-destructive test of bridge cables.3 tabs,16 figs,44 refs.

bridge engineeringbridge cableself-magnetic flux leakage detectionhigh-strength steel wirenon-destructive testcorrosion-fatigue coupling

孟庆领、杨家炳、潘鹏超、杨新磊、王宝林、宋金博

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天津城建大学土木工程学院,天津 300384

天津市交通科学研究院,天津 300060

江西交通职业技术学院路桥工程学院,江西南昌 330013

悉尼大学工程学院,新南威尔士悉尼 NSW 2006

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桥梁工程 桥梁拉索 自漏磁检测 高强钢丝 无损检测 腐蚀-疲劳耦合

国家自然科学基金项目江西省交通运输厅科技计划江西省03专项及5G项目

521081632021H0000620212ABC03A19

2024

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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