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基于压磁效应的钢筋疲劳损伤试验研究 被引量:5
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作者 张军 金伟良 毛江鸿 《浙江大学学报(工学版)》 EI CAS CSCD 北大核心 2017年第9期1681-1687,共7页
对17个HRB400热轧钢筋加工的标准试件进行轴向拉伸疲劳试验,并通过实时记录试件周围的压磁信号,研究疲劳过程中压磁信号的演变规律.结果表明:HRB400钢筋的压磁信号对疲劳损伤很敏感,相比应力-应变滞回曲线更能反映疲劳损伤过程;在静力... 对17个HRB400热轧钢筋加工的标准试件进行轴向拉伸疲劳试验,并通过实时记录试件周围的压磁信号,研究疲劳过程中压磁信号的演变规律.结果表明:HRB400钢筋的压磁信号对疲劳损伤很敏感,相比应力-应变滞回曲线更能反映疲劳损伤过程;在静力加载与循环加载过程中,压磁信号曲线都存在一个相对稳定的极值比;不同疲劳阶段的压磁滞回曲线存在显著差别,根据滞回曲线极值点的变化可预测疲劳失效;比较2个磁探头信号的曲线特征可初步判断失效的位置;试验得到的压磁信号演化过程符合疲劳三阶段规律,据此提出一个预测钢筋剩余疲劳寿命的方法. 展开更多
关键词 压磁效应 钢筋疲劳损伤 压磁滞回曲线 寿命预测
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产生坑蚀后钢筋疲劳性能的劣化 被引量:4
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作者 彭修宁 韦斌凝 张艳琴 《广西大学学报(自然科学版)》 CAS CSCD 北大核心 2009年第3期293-296,共4页
为研究产生局部锈坑后钢筋疲劳性能的劣化,设计了32根试件并完成了相关的试验,研究了不同锈坑深度与不同疲劳荷载循环次数下钢筋剩余强度的下降规律,反复荷载对混凝土结构的影响比人们目前所认识到的更为严重:当锈坑较浅时,锈蚀的影响... 为研究产生局部锈坑后钢筋疲劳性能的劣化,设计了32根试件并完成了相关的试验,研究了不同锈坑深度与不同疲劳荷载循环次数下钢筋剩余强度的下降规律,反复荷载对混凝土结构的影响比人们目前所认识到的更为严重:当锈坑较浅时,锈蚀的影响与疲劳荷载的作用可被作为两种独立的损伤(它们彼此间为线性关系);但当锈坑深度较深时,锈坑与循环荷载对试件的影响会产生彼此关联,相互促进的作用。 展开更多
关键词 坑蚀 钢筋疲劳 劣化 剩余强度
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电化学修复后钢筋疲劳性能试验研究 被引量:2
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作者 龙江兴 金伟良 +2 位作者 张军 毛江鸿 崔磊 《浙江大学学报(工学版)》 EI CAS CSCD 北大核心 2020年第1期64-72,共9页
为了探明电化学修复对钢筋疲劳性能的影响,开展电化学除氯和双向电迁处理后钢筋的轴向拉伸疲劳试验.基于断裂力学原理及断口微观形貌分析,揭示电化学修复技术引起钢筋疲劳性能变化的机理.结果表明,电化学除氯会引起钢筋疲劳裂纹门槛值... 为了探明电化学修复对钢筋疲劳性能的影响,开展电化学除氯和双向电迁处理后钢筋的轴向拉伸疲劳试验.基于断裂力学原理及断口微观形貌分析,揭示电化学修复技术引起钢筋疲劳性能变化的机理.结果表明,电化学除氯会引起钢筋疲劳裂纹门槛值的减小及疲劳弹性模量的退化,宏观表现为钢筋疲劳寿命减小;电化学除氯后钢筋疲劳裂纹起源于钢中白点,裂纹扩展区疲劳辉纹间距增大,瞬断区韧窝变小变浅.掺入阻锈剂的双向电迁方法对钢筋疲劳性能的负面影响较小,双向电迁修复后钢筋的疲劳断口微观形貌相对于普通钢筋未见明显变化. 展开更多
关键词 电化学除氯 双向电迁 电流密度 氢脆 钢筋疲劳
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混凝土结构内锈蚀钢筋的疲劳研究综述 被引量:3
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作者 张军 金伟良 +2 位作者 张凯 毛江鸿 李强 《水利水运工程学报》 CSCD 北大核心 2019年第6期22-30,共9页
腐蚀环境和反复荷载共同作用下混凝土结构的疲劳问题愈发突出,特别是混凝土结构在荷载作用下产生和发展的裂缝为腐蚀介质提供了快速传输通道,引起开裂区域钢筋局部坑蚀。动态荷载作用下疲劳裂纹在蚀坑底部形成并扩展,导致钢筋脆性断裂,... 腐蚀环境和反复荷载共同作用下混凝土结构的疲劳问题愈发突出,特别是混凝土结构在荷载作用下产生和发展的裂缝为腐蚀介质提供了快速传输通道,引起开裂区域钢筋局部坑蚀。动态荷载作用下疲劳裂纹在蚀坑底部形成并扩展,导致钢筋脆性断裂,进而导致混凝土构件的疲劳失效。回顾并分析了混凝土裂缝对钢筋疲劳性能的影响、坑蚀钢筋疲劳性能研究进展和基于弱磁效应的钢筋疲劳研究,指出掌握坑蚀钢筋的裂纹扩展行为是进行服役混凝土结构疲劳寿命预测的关键。弱磁效应能够实时地表征锈蚀钢筋的疲劳断裂行为,建立基于弱磁理论的锈蚀钢筋等效裂纹扩展长度和应力强度因子变幅表征方法,是服役钢筋混凝土结构疲劳寿命预测的一个创新方法。 展开更多
关键词 混凝土结构 锈蚀钢筋 钢筋疲劳 弱磁理论 寿命预测
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钢筋腐蚀疲劳共同作用机理与寿命预测 被引量:1
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作者 黄滢 卫军 +1 位作者 董荣珍 王陈贵生 《水利水运工程学报》 CSCD 北大核心 2016年第2期32-38,共7页
为了准确计算钢筋腐蚀疲劳寿命,依据金属力学、电化学、断裂力学的基本原理,对混凝土中脱钝钢筋的腐蚀介质和疲劳荷载共同作用交互机理进行研究,建立脱钝后钢筋在疲劳荷载作用下同时考虑弹性变形、塑性变形和电化学作用的钢筋腐蚀速率模... 为了准确计算钢筋腐蚀疲劳寿命,依据金属力学、电化学、断裂力学的基本原理,对混凝土中脱钝钢筋的腐蚀介质和疲劳荷载共同作用交互机理进行研究,建立脱钝后钢筋在疲劳荷载作用下同时考虑弹性变形、塑性变形和电化学作用的钢筋腐蚀速率模型,在此基础上构建了圆柱形钢筋腐蚀疲劳应力强度因子幅值的计算模型。定量分析了腐蚀疲劳裂纹扩展门槛值的理论计算模型以及钢筋腐蚀疲劳裂纹扩展模型,提出了腐蚀介质和疲劳荷载共同作用下钢筋寿命预测模式。利用已有文献中钢棒腐蚀疲劳试验结果对本文提出的模型以及寿命预测模式进行验证,结果表明,p H=2.5~12时钢棒腐蚀疲劳寿命计算值与试验值吻合较好,还揭示了疲劳荷载对钢筋腐蚀速度影响规律。 展开更多
关键词 钢筋腐蚀疲劳 钢筋腐蚀速率模型 寿命预测
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疲劳作用对混凝土中钢筋锈蚀氯离子临界浓度的影响 被引量:4
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作者 王永亮 蒋林华 +3 位作者 李炜 刘浩 何亮亮 朱承龙 《材料导报》 EI CAS CSCD 北大核心 2013年第24期125-128,共4页
采用三分点加载模式,对钢筋混凝土短梁进行疲劳实验。将受到不同次数疲劳作用的钢筋置于饱和Ca(OH)2溶液中,采用阶梯逐级添加的方式加入NaCl,通过测得的自腐蚀电位Ecorr和电化学阻抗技术测得的腐蚀电流密度Icorr判定钢筋锈蚀的氯离子临... 采用三分点加载模式,对钢筋混凝土短梁进行疲劳实验。将受到不同次数疲劳作用的钢筋置于饱和Ca(OH)2溶液中,采用阶梯逐级添加的方式加入NaCl,通过测得的自腐蚀电位Ecorr和电化学阻抗技术测得的腐蚀电流密度Icorr判定钢筋锈蚀的氯离子临界浓度。结果表明:疲劳作用对混凝土中钢筋锈蚀有一定的加速促进作用,使氯离子临界浓度降低,疲劳作用后的钢筋更易发生锈蚀;随疲劳作用次数的增加,钢筋锈蚀的可能性增大,锈蚀速率加快。 展开更多
关键词 疲劳作用钢筋锈蚀氯离子临界浓度 电化学阻抗谱
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桥梁结构钢筋应力集中、疲劳研究 被引量:2
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作者 段钢文 《黑龙江交通科技》 2012年第2期96-96,共1页
造成构件疲劳破坏或极限承载能力下降的内因是材料中的初始缺陷在重复荷载作用下产生应力集中,导致材料内部缺陷发展、损伤累积而强度逐渐耗散,外因则是应力反复的循环特征和累积次数。在考虑材料疲劳对结构的影响时,需首先确定材料的... 造成构件疲劳破坏或极限承载能力下降的内因是材料中的初始缺陷在重复荷载作用下产生应力集中,导致材料内部缺陷发展、损伤累积而强度逐渐耗散,外因则是应力反复的循环特征和累积次数。在考虑材料疲劳对结构的影响时,需首先确定材料的疲劳强度,然后根据重复荷载特性计算材料在确定时刻的疲劳剩余强度,最后根据材料强度与构件承载力之间的关系得出结构的疲劳剩余承载力。 展开更多
关键词 钢筋应力 钢筋疲劳性能 材料疲劳剩余强度
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电化学修复后不同含氢钢筋的低周疲劳性能试验研究 被引量:5
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作者 龚园军 张军 +3 位作者 毛江鸿 金伟良 谭昱 罗林 《材料导报》 EI CAS CSCD 北大核心 2021年第6期6146-6150,共5页
本工作通过电化学充氢试验和低周疲劳试验,分析了电化学修复后含氢钢筋的疲劳寿命、滞回曲线、剩余强度等关键力学指标。研究结果表明:钢筋试件通电时间越长、电流密度越大,钢筋内氢含量越多,且钢筋氢含量与电通量密度呈线性关系;依据... 本工作通过电化学充氢试验和低周疲劳试验,分析了电化学修复后含氢钢筋的疲劳寿命、滞回曲线、剩余强度等关键力学指标。研究结果表明:钢筋试件通电时间越长、电流密度越大,钢筋内氢含量越多,且钢筋氢含量与电通量密度呈线性关系;依据氢含量与疲劳寿命的关系可将电化学修复的负面影响程度分为A、B、C三个区域;随着氢含量增大,循环剩余强度退化加快,疲劳寿命和耗能能力降低也越显著;氢含量小于1.7×10^(-6)时,1%应力幅下钢筋试件低周疲劳寿命降低小于15%;氢含量为4.3×10^(-6)时,钢筋试件低周疲劳寿命降低73.7%。本研究结果可为电化学修复技术应用于有抗震性能要求的混凝土结构提供参考。 展开更多
关键词 钢筋低周疲劳 电化学修复 氢含量 滞回曲线 疲劳寿命
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钢筋混凝土构件疲劳设计研究 被引量:1
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作者 许家婧 叶浩天 +2 位作者 殷浩天 曹慧 张邵峰 《混凝土与水泥制品》 2022年第7期50-54,共5页
对比分析了国内外混凝土结构设计规范中关于疲劳设计的规定后发现:美国混凝土协会ACI 215R-74《疲劳荷载下混凝土结构设计规定》、日本土木工程学会JSCE 2007《混凝土结构设计规范》、我国GB 50010-2010《混凝土结构设计规范(2015年版)... 对比分析了国内外混凝土结构设计规范中关于疲劳设计的规定后发现:美国混凝土协会ACI 215R-74《疲劳荷载下混凝土结构设计规定》、日本土木工程学会JSCE 2007《混凝土结构设计规范》、我国GB 50010-2010《混凝土结构设计规范(2015年版)》均采用容许应力法进行钢筋混凝土构件疲劳设计;美国公路运输协会AASHTO LRFDUS-2017《高速公路桥梁设计规范》和欧洲CEB-FIP(2010)《混凝土结构规范》则采用疲劳极限状态设计方法,考虑荷载和抗力系数,以结构使用寿命不超过失效寿命为原则进行钢筋混凝土构件疲劳设计。在总结各国规范基础上,提出了钢筋混凝土构件的疲劳设计基本步骤,并进行了算例分析。 展开更多
关键词 钢筋混凝土构件疲劳极限状态 疲劳强度 设计方法 规范
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循环荷载作用下钢筋与混凝土界面裂纹扩展的模拟
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作者 朱庆杰 刘廷全 苏幼坡 《结构工程师》 2003年第z1期60-63,共4页
钢筋混凝土的界面脱粘是材料与结构破坏的一个重要方面,循环荷载作用下的界面疲劳问题研究越来越受到关注.基于剪切筒模型和常用加载方式,首先建立了循环荷载作用下钢筋与混凝土界面脱粘应力计算模型;借助断裂脱粘准则和描述疲劳裂纹扩... 钢筋混凝土的界面脱粘是材料与结构破坏的一个重要方面,循环荷载作用下的界面疲劳问题研究越来越受到关注.基于剪切筒模型和常用加载方式,首先建立了循环荷载作用下钢筋与混凝土界面脱粘应力计算模型;借助断裂脱粘准则和描述疲劳裂纹扩展的Paris公式,得到了界面疲劳裂纹扩展速率、扩展长度以及脱粘界面上摩擦系数与循环加载次数的关系;对处于循环荷载作用下的钢筋与混凝土界面进行裂纹扩展的模拟计算与分析. 展开更多
关键词 钢筋混凝土 界面疲劳 脱粘 循环载荷 破裂
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成都东客站承轨层桥建合一结构设计施工综合技术 被引量:1
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作者 褚松涛 曹少卫 高夕良 《科技资讯》 2010年第13期88-92,共5页
大型客站枢纽考虑列车动荷载及空间高度限制,采用了桥梁结构和建筑结构合一的结构体系;既满足结构受力要求;又满足了建筑空间要求,在车站设计施工中有推广意义。
关键词 桥建合一结构体系 钢筋接头疲劳试验 高性能砼 节点优化
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Fatigue behavior of crane beam strengthened with CFRP 被引量:2
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作者 石启印 李爱群 惠卓 《Journal of Southeast University(English Edition)》 EI CAS 2007年第4期561-565,共5页
In order to study the fatigue behavior of the damaged reinforced concrete (RC) beams strengthened by carbon fiber reinforced polymer (CFRP) laminate, three T-shaped beams strengthened by CFRP and one contrasting b... In order to study the fatigue behavior of the damaged reinforced concrete (RC) beams strengthened by carbon fiber reinforced polymer (CFRP) laminate, three T-shaped beams strengthened by CFRP and one contrasting beam are tested under fatigue loading, with the parameters of different modes of strengthening and different fatigue load levels considered. The main results obtained from the tests are: the width of the crack decreases 50. 2% to 66%, and the development of the crack is limited; the stress of steel decreases 24. 1% to 28. 2%, and the stiffness increases 14.9% to 16. 1% after being strengthened. Based on the technical specification for strengthening concrete structures with CFRP and the conclusions from the tests, a calculating scheme of the flexure stiffness is given, which can be used for reference in engineering design. Finally, some suggestions are given for design in fatigue strengthening. 展开更多
关键词 RC crane beam structure strengthening fatigue test carbon fiber reinforced polymer (CFRP)
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Numerical analysis of ultimate strength of concrete filled steel tubular arch bridges 被引量:5
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作者 谢旭 陈衡治 +1 位作者 李辉 宋世锐 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第8期859-868,共10页
The calculation of ultimate bearing capacity is a significant issue in the design of Concrete Filled Steel Tubular (CFST) arch bridges. Based on the space beam theory, this paper provides a calculation method for dete... The calculation of ultimate bearing capacity is a significant issue in the design of Concrete Filled Steel Tubular (CFST) arch bridges. Based on the space beam theory, this paper provides a calculation method for determining the ultimate strength of CFST structures. The accuracy of this method and the applicability of the stress-strain relationships were validated by comparing different existing confined concrete uniaxial constitutive relationships and experimental results. Comparison of these results indicated that this method using the confined concrete uniaxial stress-strain relationships can be used to calculate the ultimate strength and CFST behavior with satisfactory accuracy. The calculation results are stable and seldom affected by concrete con-stitutive relationships. The method is therefore valuable in the practice of engineering design. Finally, the ultimate strength of an arch bridge with span of 330 m was investigated by the proposed method and the nonlinear behavior was discussed. 展开更多
关键词 Concrete Filled Steel Tubular (CFST) Confined concrete Stress-strain relationship Ultimate strength
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Flexural fatigue strength of steel fibrous concrete containing mixed steel fibres 被引量:1
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作者 SINGH S.P. MOHAMMADI Y. MADAN S.K. 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第8期1329-1335,共7页
This paper reports investigation conducted to study the fatigue performance of steel fibre reinforced concrete (SFRC) containing fibres of mixed aspect ratio. An extensive experimental program was conducted in which 9... This paper reports investigation conducted to study the fatigue performance of steel fibre reinforced concrete (SFRC) containing fibres of mixed aspect ratio. An extensive experimental program was conducted in which 90 flexural fatigue tests were carried out at different stress levels on size 500 mm×100 mm×100 mm SFRC specimens respectively containing 1.0%, 1.5% and 2.0% volume fraction of fibres. About 36 static flexural tests were also conducted to determine the static flexural strength prior to fatigue testing. Each volume fraction of fibres incorporated corrugated mixed steel fibres of size 0.6 mm×2.0 mm×25 mm and 0.6 mm×2.0 mm×50 mm in ratio 50:50 by weight. The results are presented both as S-N relationships, with the maximum fatigue stress expressed as a percentage of the strength under static loading, and as relationships between actually applied fatigue stress and number of loading cycles to failure. Two-million-cycle fatigue strengths of SFRC containing different volume fractions of mixed fibres were obtained and compared with plain concrete. 展开更多
关键词 Fatigue strength Static flexural strength Stress level Stress ratio Steel fibre reinforced concrete (SFRC)
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Experimental study and analysis on fatigue stiffness of RC beams strengthened with CFRP and steel plate 被引量:13
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作者 卢亦焱 胡玲 +1 位作者 李杉 王康昊 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第3期701-707,共7页
The objective of this work is to investigate the fatigue behavior of reinforced concrete(RC) beams strengthened with externally bonded carbon fiber reinforced polymer(CFRP) and steel plate. An experimental investigati... The objective of this work is to investigate the fatigue behavior of reinforced concrete(RC) beams strengthened with externally bonded carbon fiber reinforced polymer(CFRP) and steel plate. An experimental investigation and theoretical analysis were made on the law of deflection development and stiffness degradation, as well as the influence of fatigue load ranges. Test results indicate that the law of three-stage change under fatigue loading is followed by both midspan deflection and permanent deflection, which also have positive correlation with fatigue load amplitude. Fatigue stiffness of composite strengthened beams degrades gradually with the increasing of number of cycles. Based on the experimental results, a theoretical model by effective moment of inertia method is developed for calculating the sectional stiffness of such composite strengthened beams under fatigue loading, and the calculated results are in good agreement with the experimental results. 展开更多
关键词 carbon fiber reinforced polymer steel plate composite strengthening technique reinforced concrete beams fatigue stiffness
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Fatigue properties of special kind of reinforced concrete composite beams
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作者 胡铁明 黄承逵 陈小锋 《Journal of Central South University》 SCIE EI CAS 2010年第1期142-149,共8页
The special reinforced concrete composite beam consists of a steel fiber reinforced self-stressing concrete composite layer and a reinforced concrete T-beam, and constructional bars are set up at their bonding interfa... The special reinforced concrete composite beam consists of a steel fiber reinforced self-stressing concrete composite layer and a reinforced concrete T-beam, and constructional bars are set up at their bonding interface. Fatigue properties of the composite beam under the action of negative moment were experimentally studied. Through inverted loading mode the load-beating state of a composite beam was simulated under the action of negative moment. With the ratios of constructional bars being 0, 0.082% and 0.164% respectively as parameters, the effects of constructional bars on the properties of composite beam, such as fatigue life, crack propagation, rigidity loss as well as damage behavior of bonding interface, were studied. The mechanism of the constructional bars on the fatigue properties of the composite beams and the restriction mechanism of crack widths and rigidity loss were analyzed. The test results show that the constructional bars can enhance the shear resistance of the bonding interface between composite layer and old concrete beam and restrict expanding of steel fiber reinforced self-stressing concrete, which are beneficial to synergistic action of composite layer and old concrete beam, to reducing the stress amplitude of bars and the crack width of composite layer, and to increasing the durability and fatigue life of the composite beam. 展开更多
关键词 steel fiber reinforced self-stressing concrete composite beam constructional bar bonding interface FATIGUE
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Prediction Model for Fatigue Stiffness Decay of Concrete Beam Based on Neural Network
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作者 王海超 何世钦 贡金鑫 《Journal of China University of Mining and Technology》 2003年第1期40-42,共3页
With the method of neural network, the processes of fatigue stiffness decreasing and deflection increasing of reinforced concrete beams under cyclic loading were simulated. The simulating system was built with the giv... With the method of neural network, the processes of fatigue stiffness decreasing and deflection increasing of reinforced concrete beams under cyclic loading were simulated. The simulating system was built with the given experimental data. The prediction model of neural network structure and the corresponding parameters were obtained. The precision and results were satisfied and could be used to investigate the fatigue properties of reinforced concrete beams in complex environment and under repeating loads. 展开更多
关键词 neural network fatigue stiffness damage cumulation plane section assumption
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Acoustic Emission Properties of Concrete Slab During Fatigue Testing with a Running-Wheel Load
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作者 Mitsuharu Shiwa Zhengwang Li +2 位作者 Takuya Maeshima Yasuhiro Koda Yasushi Tanaka 《Journal of Civil Engineering and Architecture》 2017年第3期213-221,共9页
AE (acoustic emission) signals from concrete slab during fatigue testing with a running-wheel load were evaluated. The signals were recorded by remote sensors connected to a computer network. The sensing equipment c... AE (acoustic emission) signals from concrete slab during fatigue testing with a running-wheel load were evaluated. The signals were recorded by remote sensors connected to a computer network. The sensing equipment consisted of 60 kHz resonant-type AE sensors mounted on a reinforcing steel bar as a waveguide, together with a 16-channel sensor highway AE system. Because the detected AE signals included periodic mechanical noise from the motion of the wheel, these noises were eliminated by means of signal processing. The AE waveguide measurement over a length of 3 m detected fractures as vertical and horizontal cracks in the RC (reinforced concrete) slab. Those cracks were analyzed by correlating AE parameters with macroscopic distortions and the numbers of fatigue cycles. In the AE events and AE energy, two types of AE phenomena, active region and inactive region, were observed during fatigue testing. The vertical cracks were characterized by an AE amplitude of 58 dB, a peak frequency of 30 kHz, and a ratio of the rise time to the maximum amplitude value (RA) of 100. The horizontal cracks were characterized by an AE amplitude of 85 dB, a peak frequency of 60 kHz, and an RA value of 10. 展开更多
关键词 Acoustic emission concrete slab WAVEGUIDE fatigue testing running-wheel load.
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