小空心叶片涡流测厚传感器的仿真分析与研制

发布时间：2018-02-26 10:07

  本文关键词： 涡流测厚 电磁仿真 正交实验 空心叶片 ANSYS　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：发动机叶片制造过程中的误差和各种结构形式会直接影响到叶片的疲劳特性和结构强度,使得发动机的整体性能减弱,使用寿命缩短。为了保证发动机能够安全运行,要求发动机空心叶片外表面到内表面的法线方向厚度误差必须在允许的范围之内,进而确保空心叶片的强度指标和结构参数。目前对于新型航空发动机小空心叶片壁厚的测量范围要求为0.1mm-3mm,并且测量的不确定度小于0.05mm。本课题选择了一种NDT检测法——涡流检测,设计出一种精密的小空心叶片涡流测厚传感器,在精度、稳定性以及测量范围上均能满足测量要求。本文首先介绍了涡流测厚的基本原理以及电磁场的基本理论,从电磁场基本理论出发,应用涡流阻抗分析法,总结出涡流强度与检测距离(测量厚度)和激励频率的关系,涡流传感器受到温度的影响,以及涡流的径向和纵向分布情况。然后利用有限元软件ANSYS对涡流测厚时的电磁场进行仿真分析,建立出轴对称的二维模型,考虑到周边空气,应用了远场单元,得出如下结论:测量的小空心叶片厚度发生改变时,测量线圈阻抗的虚部发生变化最为明显,这为信号的提取提供依据;施加的激励频率越大,金属基底产生的涡流集肤效应越明显,频率的增加使得线圈阻抗的虚部增加,而实部几乎不变,因此对于不同探测范围,应当选择不同的激励频率;基底上产生的涡流和线圈平均半径大致相同;不同的基底材料使得磁力线的分布截然不同,通过对比4种基底材料,铜能引起的线圈阻抗虚部的变化幅度最小,而硅钢的效果最好,引起阻抗虚部的变化幅度最大,能够拥有较好的灵敏度和稳定性。通过有限元仿真只能定性的分析各个参数的影响,并不能得到准确的数值,因此最后通过正交实验得到了各参数的最优水平和最佳组合,并经过实际测量验证,成功研制出能够满足测量精度和测量范围的涡流测厚传感器。
[Abstract]:The errors and various structural forms in the manufacturing process of engine blades will directly affect the fatigue characteristics and structural strength of the blades, which will weaken the overall performance of the engine, shorten its service life, and ensure the safe operation of the engine. The normal thickness error from the outer surface to the inner surface of the hollow blade of the engine must be within the allowable range. In order to ensure the strength index and structural parameters of the hollow blade, the current measurement range for the wall thickness of the small hollow blade of the new aeroengine is 0.1 mm ~ 3mm, and the uncertainty of the measurement is less than 0.05 mm. In this paper, a NDT detection method, eddy current test, is chosen. A precise eddy current thickness sensor with small hollow vane is designed, which can meet the measurement requirements in terms of accuracy, stability and measurement range. Firstly, the basic principle of eddy current thickness measurement and the basic theory of electromagnetic field are introduced in this paper. Based on the basic theory of electromagnetic field, the relationship between eddy current intensity and measuring distance (measuring thickness) and excitation frequency is summarized by means of eddy current impedance analysis. The eddy current sensor is affected by temperature. And the radial and longitudinal distribution of eddy current. Then the electromagnetic field of eddy current thickness measurement is simulated and analyzed by finite element software ANSYS, and an axisymmetric two-dimensional model is established. Considering the surrounding air, the far-field element is used. The following conclusions are drawn: when the thickness of the measured small hollow blade changes, the imaginary part of the measurement coil impedance changes most obviously, which provides the basis for the signal extraction. The skin effect of eddy current produced by metal substrate is more obvious, the increase of frequency makes the imaginary part of coil impedance increase, but the real part is almost unchanged. Therefore, different excitation frequency should be chosen for different detection range. The average radius of eddy current and coil on the substrate is approximately the same, and the magnetic field line is distributed differently by different substrate materials. By comparing the four kinds of substrate materials, the variation amplitude of the imaginary part of the coil impedance caused by copper energy is the smallest. The effect of silicon steel is the best, the change of impedance imaginary part is the largest, and it can have better sensitivity and stability. The influence of each parameter can only be qualitatively analyzed by finite element simulation, but the exact value can not be obtained. Finally, the optimal level and combination of the parameters are obtained by orthogonal experiment, and the eddy current thickness sensor which can satisfy the measuring accuracy and range is developed successfully after the actual measurement.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V263;TP212

【参考文献】

中国期刊全文数据库 前1条

1 郝拉娣;张娴;刘琳;;科技论文中正交试验结果分析方法的使用[J];编辑学报;2007年05期

中国博士学位论文全文数据库 前1条

1 高军哲;多频涡流无损检测的干扰抑制和缺陷检测方法研究[D];国防科学技术大学;2011年

中国硕士学位论文全文数据库 前1条

1 于亚婷;电涡流传感器的电磁场仿真分析[D];电子科技大学;2005年

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