细径棒材在线相控阵超声无损检测关键技术的研究

发布时间：2018-03-16 18:30

本文选题：细径棒材　切入点：在线检测　出处：《浙江大学》2017年硕士论文　论文类型：学位论文

【摘要】：棒材作为一种基础的现代化工业组成部分,应用于各个领域,为我国国民经济发展和现代化国防建设做出了重大贡献。但是由于棒材在锻造和轧制过程中会出现纵向裂纹、横向裂纹、鳞状折叠等缺陷,一旦棒材在高温、高压、交变载荷等恶劣的使用环境中失效会导致严重的事故,造成重大的经济损失和人员伤亡,因而需要对棒材进行无损检测以确保其质量可靠。目前,在众多棒材无损检测技术中,超声无损检测技术以其穿透性强、分辨率高、检测灵敏度高、携带信息丰富、对人体安全无害等优势,成为棒材缺陷检测最为有效的手段。然而,随着社会生产力的不断提升和社会经济水平的快速发展,常规超声棒材在线无损检测技术已经无法满足现代化棒材检测的需求,相控阵超声无损检测技术以其灵活、快速、准确、电子化等优势,成为棒材在线超声无损检测的研究热点。基于以上背景,本论文结合国家自然科学基金项目“圆柱类部件高性能自动化相控阵超声成像检测理论与技术的研究”(NO.51675480),提出开展细径棒材在线相控阵超声无损检测关键技术的研究。在研究细径棒材相控阵超声无损检测基础理论以及实现凹面线型相控阵超声换能器声场建模的基础上,对直入射凹面线型相控阵超声换能器参数进行分析及仿真优化,并结合相控阵超声无损检测技术和机电一体化技术,通过开展基于相控阵超声的细径棒材在线无损检测技术的研究,研发相应的系统,实现细径棒材轮廓和缺陷的检测。同时,还进行实验研究,为细径棒材的自动化在线超声无损检测打下必要的技术基础。具体研究工作包括:第一章,论述了棒材的重要作用以及对国民经济和社会发展的重要意义,总结分析了棒材无损检测技术的研究现状及其发展趋势,指出了细径棒材相控阵超声无损检测技术在线应用的优势,明确了本文的研究内容,为后续章节的研究指明了方向。第二章,根据惠更斯原理,实现了相控阵超声换能器声束的聚焦、偏转以及聚焦加偏转的电子扫查,分析了超声波在水钢界面入射时发生的反射、折射和波型转换现象,并根据细径棒材的缺陷种类提出了相应的检测方式。此外,采用解析法推导出了凹面线型相控阵超声换能器的声压分布公式,完成了该类相控阵换能器声场的理论建模,并根据换能器参数选择的优化目标,研究了相邻阵元对应的圆心角、阵元宽度、动态阵元总数以及工作频率对凹面线型相控阵超声换能器性能的影响。第三章,在对细径棒材的外形轮廓检测方式介绍的基础上,完成了超声回波信号的包络提取,并对超声波在耦合水中的声速进行了温度补偿,实现了对细径棒材外形轮廓的精确测量。同时,在对直入射和斜入射凹面线型相控阵超声换能器的检测声场理论分析的基础上,通过建立棒材纵向和横向裂纹缺陷模型,开展了细径棒材缺陷相控阵超声检测的仿真研究,为后续的研发提供了进一步的理论支撑。第四章,完成了细径棒材相控阵超声无损检测系统总体方案的设计,明确了超声无损检测系统的目标功能,规划了系统的总体实施方案,根据分布式系统体系架构,完成了硬件模块、软件模块的开发和整个系统的集成,实现了细径棒材在线相控阵超声无损检测原理样机的研发,并且通过对设置有人工缺陷的棒材进行缺陷检测实验研究,证实了本论文所研发理论与技术的可行性。第五章,对全文的研究工作进行了总结,对将来的进一步研究进行了展望。
[Abstract]:Bar as a basic part of modern industry, used in various fields, made a significant contribution to the development of China's national economy and modernization of national defense construction. But because the bar will appear in the longitudinal crack, forging and rolling process of transverse crack, squamous folding defects, once the bar in high temperature, high pressure, failure will lead to serious the accident using alternating load in harsh environment, causing significant economic losses and casualties, and thus the need for nondestructive testing to ensure the reliable quality of the bar. At present, many bars in NDT, ultrasonic nondestructive testing technology with its strong penetrability, high resolution, high detection sensitivity, carrying abundant information safe on the human body and other advantages, has become the most effective means for bar defect detection. However, with the rapid increase of social productivity and social economic level The exhibition, conventional ultrasound online bar nondestructive testing technology has been unable to meet the demand of modern bar detection, phased array ultrasonic nondestructive testing technology with its flexible, fast, accurate, electronic and other advantages, has become a hot topic of NDT ultrasonic bar. The above background based on cylindrical parts high performance automatic detection theory and phased array ultrasonic imaging the National Natural Science Fund Project "with the" (NO.51675480), the study of small diameter online bar key technology of phased array ultrasonic detection. Based on the study of small diameter bar phased array ultrasonic nondestructive testing theory and Realization of concave linear phased array ultrasonic transducer sound field modeling, to shoot into the concave linear phased array ultrasonic transducer parameters analysis and simulation optimization, combined with phased array ultrasonic detection technology and Mechatronics Based on the research of ultrasonic phased array technology, based on the fine diameter bar online nondestructive testing technology, to develop the corresponding system, realize the detection of small diameter bar contours and defects. At the same time, also to conduct experimental research, non-destructive technology base necessary for online detection of ultrasonic automated lay small diameter bar. The main research work is as follows: first chapter, discusses the importance of the bar and the national economic and social development, summarizes and analyzes the research status and development trend of the nondestructive testing technology of bar, pointed out that the small diameter bar phased array ultrasonic online detection technology application advantages, clear the research content of this paper, pointed out the direction for further research. The second chapter, according to the Huygens principle, realization of the phased array ultrasonic transducer beam, deflection and electronic focusing with deflection scanning, analysis of ultrasonic in water When the incident occurred steel interface reflection, refraction and wave mode conversion phenomenon, and puts forward corresponding detection methods according to the defect type small diameter bar. In addition, deduced the formula of pressure distribution of linear phased array ultrasonic transducer with concave analytical method, complete the theoretical model this phased array transducer sound field, and according to the optimization goal of transducer parameter selection, the adjacent array elements corresponding to the central angle, width of element, influence the dynamic total element number and the working frequency of the concave linear phased array ultrasonic transducer. The third chapter, based on the introduction of small diameter bar contour detection methods, completed the envelope extraction of ultrasonic echo signals, and the in the ultrasonic coupling water velocity of temperature compensation, realize the accurate measurement of small diameter bar shape. At the same time, in the normal incidence and oblique incidence of concave linear phase control Based on analysis of the ultrasonic transducer array acoustic theory, through the establishment of longitudinal and transverse crack defect model, carry out the simulation research of phased array ultrasonic testing defects of steel bars of small diameter, provides further theoretical support for subsequent research. The fourth chapter, completed the design of small diameter bar phased array ultrasonic inspection system. The ultrasonic nondestructive testing system of target function, planning the overall system implementation plan, according to the distributed system architecture, hardware module, software module and integrated development of the whole system, the realization of the development of small diameter bar phased array ultrasonic nondestructive testing principle prototype, and experimental study on detection of defects by artificial bar the defect on the set, proved the feasibility of the development of theory and technology. In the fifth chapter, the research work of the full text The conclusion is summarized and the further research in the future is prospected.

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG115.285

【参考文献】