电磁声发射机理及数值分析研究

发布时间：2018-05-07 23:22

  本文选题：电磁声发射 + 铝板裂纹　； 参考：《东北石油大学》2017年硕士论文

【摘要】：电磁声发射检测技术是近几年出现的一项新的无损检测技术,它通过对金属材料的局部电磁加载产生洛伦兹力激发声发射现象从而实现对导体材料缺陷的检测,确定设备或构件的完整性,因此对电磁声发射技术的研究具有一定的理论意义,另外因不需对测试构件进行整体加载而在工程声发射检测中具有非常重要的应用价值。本文通过理论分析电磁声发射的产生机理,利用有限元分析软件,建立3D电磁场对电磁声发射的模型进行求解分析,并且通过搭建电磁声发射检测实验平台,对不同尺寸裂纹进行电磁激励下的声发射实验研究,完成铝板裂纹的电磁声发射检测及评价方法。主要研究内容如下:1、根据电磁学电致涡流原理,对通电的空心圆柱线圈进行电磁场分析,结合力学以及声发射技术分析了电磁声发射的产生机理,获得其数学模型。2、利用COMSOL有限元分析软件对电磁激励系统的参数进行设计,确定了最佳激励线圈结构参数和电磁激励参数,并对不同尺寸的裂纹进行仿真研究,分析了裂纹长度和裂纹深度的变化对电磁激励效果的影响。3、基于EMAE实验平台,对不同尺寸的裂纹进行电磁声发射实验研究,利用特性参数分析、频谱分析以及小波包分析等多种手段进行信号处理和信息挖掘,获得能用于EMAE测试的主要声发射特征参量和波形参量。4、通过对EMAE实验信号进行分解和重构,获得表征缺陷特征的声发射波形,并对根据波形重新生成典型AE特征参量,进而确定特征参量随裂纹长度和裂纹深度演变规律,完成电磁声发射对于含不同裂纹尺寸铝板的检测及评价方法,为其工程应用奠定基础。
[Abstract]:Electromagnetic acoustic emission (EAE) detection is a new nondestructive testing technique in recent years. It can detect the defects of conductor materials by the phenomenon of Lorentz force excited acoustic emission caused by local electromagnetic loading of metal materials. To determine the integrity of the equipment or components, the study of electromagnetic acoustic emission technology has a certain theoretical significance, in addition, it has a very important application value in engineering acoustic emission detection because it does not need to load the whole test components. In this paper, the mechanism of electromagnetic acoustic emission is analyzed theoretically, and the 3D electromagnetic field model is established by using finite element analysis software, and the experimental platform of electromagnetic acoustic emission detection is built. The acoustic emission (AE) experiments of cracks with different sizes were carried out under electromagnetic excitation. The detection and evaluation of cracks in aluminum plates were carried out by electromagnetic acoustic emission (EOAE). The main research contents are as follows: according to the electromagnetic-induced eddy current principle, the electromagnetic field of the electrically charged hollow cylindrical coil is analyzed, and the mechanism of electromagnetic acoustic emission is analyzed in combination with mechanics and acoustic emission technology. The mathematical model .2is obtained. The parameters of electromagnetic excitation system are designed by using COMSOL finite element analysis software, and the structure parameters and electromagnetic excitation parameters of the optimal excitation coil are determined, and the cracks of different sizes are simulated. The influence of crack length and crack depth on the electromagnetic excitation effect is analyzed. Based on the EMAE experimental platform, the electromagnetic acoustic emission experiments of cracks of different sizes are carried out, and the characteristic parameters are analyzed. Spectrum analysis and wavelet packet analysis are used for signal processing and information mining to obtain the main acoustic emission characteristic parameters and waveform parameters. 4, which can be used in EMAE testing. The EMAE experimental signals are decomposed and reconstructed. Acoustic emission waveforms representing defect characteristics are obtained, and the characteristic parameters of AE are regenerated according to the waveforms, and the evolution of characteristic parameters with crack length and crack depth is determined. The detection and evaluation method of electromagnetic acoustic emission (EAE) for aluminum plate with different crack sizes is completed, which lays a foundation for its engineering application.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG115.284
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本文编号：1858926