基于ACFM的焊缝表面裂纹缺陷检测系统开发

发布时间：2018-07-03 10:52

本文选题：焊缝表面检测 + 交流电磁场检测　；参考：《中国石油大学(华东)》2015年硕士论文

【摘要】：论文以焊缝表面裂纹缺陷为研究对象,围绕焊缝表面裂纹交流电磁场检测(ACFM)系统开发展开研究,针对焊缝结构特点和性质,对比分析常用焊缝检测技术优缺点,借助ANSYS建立仿真模型,仿真分析平板对接焊缝、管道焊缝、T型管节点等焊缝表面裂纹缺陷。重点基于GMR传感器优化设计探头,搭建系统硬件平台和软件平台,设计开发基于GMR传感器的集焊缝检测-信号处理-智能识别判定为一体的焊缝表面裂纹缺陷ACFM检测系统。通过试件检测试验测试,表明GMR传感器焊缝表面裂纹缺陷ACFM检测系统具有较高的线性度和灵敏度。论文主要从以下三个方面展开研究:(1)焊缝表面裂纹缺陷ACFM检测理论研究与数值仿真分类汇总常见焊缝表面裂纹缺陷,总结不同结构焊缝表面裂纹特点,借助ANSYS仿真软件,建立不同形状、不同尺寸、不同特点的焊缝表面裂纹缺陷ACFM检测模型,设置理想边界条件,加载正弦激励交流电,分析和提取焊缝表面裂纹区域磁场畸变特征,为焊缝表面裂纹检测探头设计奠定基础。(2)焊缝表面裂纹检测探头优化设计与系统搭建设计并制作适合于焊缝表面裂纹检测的小型线圈传感器ACFM探头,结合实验室ACFM检测系统,适用于焊缝表面裂纹检测,具有良好可靠度和准确性。设计开发基于GMR传感器ACFM检测系统,设计GMR传感器电路,将磁场信号采集与放大滤波集成于探头内部实现整体封装,提高探头精度;引入大容量锂电池,设计稳压电路,增强系统灵活性和适用性;建立缺陷库,改善缺陷智能识别软件,完成集焊缝检测-信号处理-智能识别判定为一体的GMR传感器ACFM焊缝表面裂纹缺陷检测系统。(3)焊缝表面裂纹ACFM检测系统实验测试采用包括平板焊缝、管道对接焊缝以及管节点焊缝等多种焊缝试件,对设计开发焊缝表面裂纹ACFM检测系统的功能性、提离高度以及检测稳定性等关键指标进行实验测试,实验结果表明:本系统能够较好探测焊缝表面缺陷的存在,提取和绘制的缺陷特征信号曲线规律正确,提离缺陷识别准确性;对比分析线圈传感器和GMR传感器检测结果表明,线圈传感器测量范围大,抗干扰性相对较强;GMR传感器线性度较好,信号特征值稳定性高。
[Abstract]:In this paper, the weld surface crack defects are studied, and the development of AC electromagnetic field (ACFM) system for weld surface crack detection (ACFM) is studied. The advantages and disadvantages of common weld detection techniques are compared and analyzed according to the characteristics and properties of weld structure. A simulation model was established with ANSYS to simulate and analyze the surface crack defects of flat butt weld and T-shaped pipe joint. Based on the optimum design of the probe of GMR sensor, the hardware platform and software platform of the system are built, and the ACFM detection system of weld surface crack defect based on GMR sensor is designed and developed, which integrates welding seam detection, signal processing and intelligent identification. The test results show that the ACFM detection system for weld surface crack defects of GMR sensor has high linearity and sensitivity. This paper mainly studies the following three aspects: (1) theoretical research and numerical simulation of weld surface crack defects ACFM detection theory and numerical simulation to summarize the common weld surface crack defects, summed up the characteristics of weld surface cracks in different structures, with the help of ANSYS simulation software. An ACFM detection model of weld surface crack defects with different shapes, sizes and characteristics is established, and ideal boundary conditions are set up, and sinusoidal excitation AC current is loaded to analyze and extract the magnetic field distortion characteristics of weld surface crack area. It lays a foundation for the design of weld surface crack detection probe. (2) the optimum design of weld surface crack detection probe and the design of the system and the fabrication of the small coil sensor ACFM probe suitable for weld surface crack detection, combined with the laboratory ACFM detection system. It is suitable for weld surface crack detection and has good reliability and accuracy. Based on the GMR sensor ACFM detection system, the GMR sensor circuit is designed. The magnetic field signal acquisition and amplifying filter are integrated into the probe to realize the whole package, to improve the accuracy of the probe, to introduce the large capacity lithium battery, and to design the voltage stabilizing circuit. Enhance the flexibility and applicability of the system, build the defect library, improve the defect intelligent recognition software, The GMR sensor ACFM weld surface crack detection system is completed. (3) the weld surface crack ACFM detection system is tested with plate weld seam. The functions, lift height and stability of the ACFM testing system for weld surface cracks are tested by experiments on pipe butt weld, pipe joint weld and other welds, and the key indexes such as the function of ACFM detection system, the lift height and the detection stability of the weld surface crack are tested. The experimental results show that the system can detect the defects on the weld surface better, the characteristic signal curves of the extracted and drawn defects are correct, and the identification accuracy of the lifting defects is correct, and the detection results of coil sensors and GMR sensors show that, The measurement range of the coil sensor is large, the anti-interference is relatively strong, the linearity of the GMR sensor is better and the stability of the signal eigenvalue is high.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG441.7

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