铁磁性构件的脉冲涡流无损检测方法研究

发布时间：2018-02-22 07:16

本文关键词： 无损检测铁磁性材料脉冲涡流缺陷信号采集　出处：《江苏理工学院》2015年硕士论文　论文类型：学位论文

【摘要】：脉冲涡流检测已经广泛应用于工业检测方面,由于其设备简单、操作方便、不易受干扰、检测速度快、非接触等优点,深得检测人员的青睐。本文根据脉冲涡流检测原理,采用COMSOL有限元软件对检测探头尺寸进行了仿真优化,以及改变材料电导率、磁导率大小对仿真试验的影响。为了研究铁磁性材料表面裂纹缺陷规律,设计了脉冲涡流检测系统。该检测系统的主要组成部分包括信号发生器、功率放大电器、传感器、信号调理电路、数据采集卡和计算机等,其中传感器是由绕制在铁氧体上的圆柱形激励线圈和霍尔传感器组成。实验平台的搭建是以MATLAB软件的信号采集以及分析为基础,本课题依次采用PWM脉冲、SPWM脉冲激励波对试件缺陷进行检测研究,通过DAQ采集卡对激励波形检测,实现脉冲涡流响应信号的同步采样。通过MATLAB软件对铁磁性试件涡流采集信号进行处理与分析,提取了缺陷的峰值电压、频谱特征量,用于对试件缺陷的分析。根据上述各种缺陷曲线的相互关系,进行检测评估。通过课题研究得到了:宽扁型探头对铁磁性材料检测更加有效;不同激励方波参数变化对脉冲检测的影响规律;SPWM脉冲调制波频率变化对于检测的影响。本课题的研究成功的发现了新的脉冲涡流检测方法,对预定的假想进行了实验验证。
[Abstract]:Pulse eddy current testing has been widely used in industrial testing, because of its simple equipment, easy operation, easy to be interfered, fast detection speed, non-contact and so on, it has been favored by the detection personnel. In this paper, according to the principle of pulse eddy current testing, The COMSOL finite element software was used to simulate and optimize the size of the probe, and the influence of changing the conductivity and permeability of the material on the simulation test was carried out. In order to study the law of surface crack defect of ferromagnetic material, The main components of the system include signal generator, power amplifier, sensor, signal conditioning circuit, data acquisition card and computer. The sensor is composed of cylindrical excitation coil and Hall sensor wound on ferrite. The experimental platform is based on the signal acquisition and analysis of MATLAB software. In this paper, the PWM pulse pulse excitation wave is used to detect the defect of the specimen in turn, and the excitation waveform is detected by the DAQ acquisition card. In order to realize synchronous sampling of pulse eddy current response signal, the MATLAB software is used to process and analyze the eddy current acquisition signal of ferromagnetic specimen, and the peak voltage and spectrum characteristic of the defect are extracted. It is used to analyze the defect of the specimen. According to the relationship of each defect curve mentioned above, the detection and evaluation are carried out. Through the research of the subject, it is concluded that the wide flat probe is more effective for the detection of ferromagnetic material; The influence of different exciting square wave parameters on pulse detection is discussed. In this paper, a new method of pulse eddy current detection is found successfully, and the predefined hypothesis is verified by experiments.
【学位授予单位】：江苏理工学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB302.5

【参考文献】