基于电磁脉冲涡流的桥梁内部钢筋锈蚀度检测试验研究
发布时间：2019-03-06 11:44
【摘要】：随着钢筋混凝土结构的应用与发展,其耐久性成为人们关注的焦点。钢筋锈蚀是钢筋混凝土结构耐久性失效形式中最为严重的类型,也是钢筋混凝土桥梁破坏的主要原因。因此,定期检测混凝土桥梁中钢筋锈蚀状况显得尤为重要。目前已有的检测技术主要有破损检测技术、半破损检测技术和无损检测技术三大类。本文研究的脉冲涡流检测属于无损检测技术,具有安全性好、成本低、无须停机、无须预埋、无须拆除混凝土保护层等优点,成为无损检测钢筋混凝土结构的一种高效方法。论文基于电磁脉冲涡流工作原理,自行设计了一套检测系统,完成了基于电磁脉冲涡流的桥梁内部钢筋锈蚀度ANSYS磁场仿真及试验研究,为钢筋锈蚀度的检测探索了一种新方法。论文主要研究内容和结论包括:①在对脉冲涡流的工作原理、趋肤效应、渗透深度以及影响感应电压的几个重要参数分析的基础上,设计了一套电磁脉冲涡流检测系统,并介绍了系统各组成部分的技术指标和功能特性。②完成了锈蚀钢筋电磁脉冲涡流检测试验。检测结果表明,在现有实验条件下,本检测系统在一定提离范围内皆可有效检测出缺陷位置,且锈蚀缺陷越深或者越宽,感应电压幅值会越小,感应电压峰-峰值会越小,脉冲上升沿时间会越小,因此本系统不仅可检测缺陷位置,还能分辨出缺陷的大小,证明该系统是可行的,同时本系统还可以有效检测到钢筋位置和进行钢筋直径大小的比较。③完成了不同钢筋直径的混凝土试块脉冲涡流检测试验。分别采用人工模拟和电化学的方法对试块中的钢筋进行锈蚀,使用本检测系统对不同锈蚀程度的试块进行检测,试验结果表明,钢筋混凝土试块与裸钢筋检测结果有相同的规律。④完成了ANSYS有限元分析软件的仿真分析。首先对电磁场有限元分析做简要介绍,再对混凝土构件中钢筋锈蚀度脉冲涡流检测进行有限元建模与仿真,在混凝土构件一定的保护层厚度下,提取不同锈蚀度下的仿真结果,并与试验结果对比吻合较好。因此,本文探索研究的基于电磁脉冲涡流技术的桥梁内部钢筋锈蚀度检测方法有效可行,且该方法操作方便、结果可靠,具有一定的应用前景。
[Abstract]:With the application and development of reinforced concrete structure, its durability has become the focus of attention. Steel corrosion is the most serious type of durability failure of reinforced concrete structures, and is also the main cause of failure of reinforced concrete bridges. Therefore, it is very important to detect the corrosion of steel bars in concrete bridges on a regular basis. At present, the existing testing techniques mainly include damage testing technology, semi-destructive testing technology and non-destructive testing technology. Pulse eddy current testing is a non-destructive testing technology. It has the advantages of good security, low cost, no need to stop, no need to be buried, no need to remove concrete protective layer, and so on. It has become an efficient method for non-destructive testing of reinforced concrete structures. Based on the principle of electromagnetic pulse eddy current, this paper designs a self-designed testing system, and completes the ANSYS magnetic field simulation and experimental study of steel bar corrosion degree in bridge based on electromagnetic pulse eddy current, and explores a new method for detecting steel bar corrosion degree. The main research contents and conclusions of this paper are as follows: 1 based on the analysis of several important parameters such as the principle of pulse eddy current, skin effect, penetration depth and the influence of induced voltage, an electromagnetic pulse eddy current testing system is designed, which is based on the analysis of the principle of pulse eddy current, skin effect, penetration depth and induction voltage. The technical indexes and functional characteristics of each component of the system are introduced. 2 the electromagnetic pulse eddy current testing test of corroded steel bars is completed. The detection results show that under the existing experimental conditions, the detection system can effectively detect the defect position within a certain range of lift-off, and the deeper or wider the rust defect is, the smaller the induced voltage amplitude will be, and the smaller the induced voltage peak-peak value will be, the greater the corrosion defect is, the smaller the induced voltage peak-peak value will be. The pulse rising edge time will be smaller, so this system not only can detect the defect location, but also can distinguish the size of the defect, which proves that the system is feasible. At the same time, the system can detect the position of steel bar effectively and compare the diameter of steel bar. 3. The pulse eddy current test of concrete test block with different steel bar diameter can be completed. Artificial simulation and electrochemical method were used to corrode the steel bars in the test block. The testing system was used to detect the specimens with different degree of corrosion. The test results showed that the steel bars in the test block were corroded by the method of artificial simulation and electrochemistry. There is the same law between the test block of reinforced concrete and the test result of bare steel bar. 4 the simulation analysis of ANSYS finite element analysis software is completed. Firstly, the finite element analysis of electromagnetic field is briefly introduced, and then the finite element modeling and simulation of pulsed eddy current testing of steel bar corrosion degree in concrete members are carried out, and the simulation results under different corrosion degrees are extracted under certain cover thickness of concrete members. The results are in good agreement with the experimental results. Therefore, this paper explores the electromagnetic pulse eddy current technology based on the bridge internal reinforcement corrosion detection method is effective and feasible, and the method is convenient to operate, the results are reliable, and has a certain prospect of application.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U446
本文编号：2435494
[Abstract]:With the application and development of reinforced concrete structure, its durability has become the focus of attention. Steel corrosion is the most serious type of durability failure of reinforced concrete structures, and is also the main cause of failure of reinforced concrete bridges. Therefore, it is very important to detect the corrosion of steel bars in concrete bridges on a regular basis. At present, the existing testing techniques mainly include damage testing technology, semi-destructive testing technology and non-destructive testing technology. Pulse eddy current testing is a non-destructive testing technology. It has the advantages of good security, low cost, no need to stop, no need to be buried, no need to remove concrete protective layer, and so on. It has become an efficient method for non-destructive testing of reinforced concrete structures. Based on the principle of electromagnetic pulse eddy current, this paper designs a self-designed testing system, and completes the ANSYS magnetic field simulation and experimental study of steel bar corrosion degree in bridge based on electromagnetic pulse eddy current, and explores a new method for detecting steel bar corrosion degree. The main research contents and conclusions of this paper are as follows: 1 based on the analysis of several important parameters such as the principle of pulse eddy current, skin effect, penetration depth and the influence of induced voltage, an electromagnetic pulse eddy current testing system is designed, which is based on the analysis of the principle of pulse eddy current, skin effect, penetration depth and induction voltage. The technical indexes and functional characteristics of each component of the system are introduced. 2 the electromagnetic pulse eddy current testing test of corroded steel bars is completed. The detection results show that under the existing experimental conditions, the detection system can effectively detect the defect position within a certain range of lift-off, and the deeper or wider the rust defect is, the smaller the induced voltage amplitude will be, and the smaller the induced voltage peak-peak value will be, the greater the corrosion defect is, the smaller the induced voltage peak-peak value will be. The pulse rising edge time will be smaller, so this system not only can detect the defect location, but also can distinguish the size of the defect, which proves that the system is feasible. At the same time, the system can detect the position of steel bar effectively and compare the diameter of steel bar. 3. The pulse eddy current test of concrete test block with different steel bar diameter can be completed. Artificial simulation and electrochemical method were used to corrode the steel bars in the test block. The testing system was used to detect the specimens with different degree of corrosion. The test results showed that the steel bars in the test block were corroded by the method of artificial simulation and electrochemistry. There is the same law between the test block of reinforced concrete and the test result of bare steel bar. 4 the simulation analysis of ANSYS finite element analysis software is completed. Firstly, the finite element analysis of electromagnetic field is briefly introduced, and then the finite element modeling and simulation of pulsed eddy current testing of steel bar corrosion degree in concrete members are carried out, and the simulation results under different corrosion degrees are extracted under certain cover thickness of concrete members. The results are in good agreement with the experimental results. Therefore, this paper explores the electromagnetic pulse eddy current technology based on the bridge internal reinforcement corrosion detection method is effective and feasible, and the method is convenient to operate, the results are reliable, and has a certain prospect of application.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U446
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1 黄琛;铁磁性构件脉冲涡流测厚理论与仪器[D];华中科技大学;2011年
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