飞机油箱搅拌摩擦焊缝超声特征成像方法研究

发布时间：2018-05-07 22:17

本文选题：无损检测 + 特征成像　；参考：《南昌航空大学》2016年硕士论文

【摘要】：飞机油箱是飞机的源力系统,其主要任务是贮存燃油并为发动机供应燃料,确保发动机在飞行过程中的稳定性。目前,飞机油箱蒙皮焊接主要采用搅拌摩擦焊技术,该技术具有优质、高效、低耗、变形小、无污染等优点,广泛应用于薄板焊接技术领域。在飞机油箱蒙皮的焊接过程中,由于人为选择焊接工艺参数不当及环境因素影响[34],焊缝内会出现紧贴、细小和取向复杂的缺陷,这些缺陷往往会造成母材间的脱落和漏油的安全隐患,给国家财产带来巨大损失。无损检测是一种有效的质量评价手段,可以帮助企业筛选出合格的飞机油箱,进而提高飞机油箱在使用过程中的安全性和可靠性。课题针对飞机油箱焊缝中的常见缺陷问题,在传统飞机油箱焊缝手动超声检测的基础上,结合自动化检测技术,研制出多探头多角度的超声特征成像检测系统。系统对多通道的超声全波列检测信号进行分析和处理,以缺陷信号的回波幅值和相位信息为特征参量进行超声特征成像,以直观的图像形式显现出缺陷的位置和大小。通过设计高精度的机电控制系统,确保机械传动精度优于0.2mm;系统适用于焊缝内紧贴、细小和取向复杂的缺陷检测。对于紧贴型缺陷,系统可以检测出距焊缝表面0.1mm内的紧贴型缺陷。对于细小、取向复杂的缺陷,系统可以检测出壁厚0.3mm的纵向缺陷;实验中采用横波和纵波联合检测方式,超声波从不同角度对同一缺陷进行检测,杜绝了缺陷的漏检和误判,同时提高灵敏度和分辨率。检测完成之后,可以回调历史检测记录,供检测人员对有异议的检测结果重新审阅。论文主要介绍飞机油箱焊缝超声特征成像检测系统的检测原理、特点和方法,并基于油箱焊缝检测要求设计相应的探头组支架和机电控制系统,完成飞机油箱焊缝的自动化检测控制。制作带有人工缺陷的标准试样,获得特征图像,验证了系统的检测能力和检测精度等。
[Abstract]:The main task of the aircraft fuel tank is to store fuel and supply fuel to the engine to ensure the stability of the engine during flight. At present, friction stir welding (FSW) technology is mainly used in aircraft fuel tank skin welding, which has the advantages of high quality, high efficiency, low consumption, low deformation, no pollution and so on, so it is widely used in the field of thin plate welding. In the welding process of aircraft fuel tank skin, due to the improper selection of welding process parameters and the influence of environmental factors [34], there will be defects in the weld seam, which are tight, fine and complex orientation. These defects often lead to the loss of base materials and oil spills, resulting in huge losses to national property. Non-destructive testing (NDT) is an effective means of quality evaluation, which can help enterprises to screen out qualified aircraft fuel tanks and improve the safety and reliability of aircraft fuel tanks in the process of operation. Aiming at the common defects in the welding seam of aircraft fuel tank, a multi-probe and multi-angle ultrasonic characteristic imaging detection system is developed on the basis of traditional ultrasonic inspection of aircraft fuel tank welding seam and automatic detection technology. The multi-channel ultrasonic full-wave train detection signal is analyzed and processed. The echo amplitude and phase information of the defect signal are taken as the characteristic parameters for ultrasonic feature imaging. The position and size of the defect are displayed in the form of visual image. The high precision electromechanical control system is designed to ensure the accuracy of mechanical transmission is better than 0.2 mm. The system is suitable for the defect detection of tight, fine and complex orientation inside the weld. For the fastening type defect, the system can detect the fastening type defect in the 0.1mm from the weld surface. The longitudinal defect of 0.3mm with wall thickness can be detected by the system for the small and complex orientation. In the experiment, the same defect is detected from different angles by ultrasonic wave combined with S-wave and P-wave, and the missing detection and misjudgment of the defect are eliminated. At the same time, the sensitivity and resolution are improved. Upon completion of the test, the history of the test can be callback for reexamination of dissenting test results. This paper mainly introduces the detection principle, characteristics and methods of ultrasonic characteristic imaging detection system for aircraft fuel tank weld seam, and designs the corresponding probe support and electromechanical control system based on the inspection requirements of oil tank weld seam. Complete the automatic inspection and control of the welding seam of the aircraft fuel tank. The standard samples with artificial defects are made and the feature images are obtained. The detection ability and accuracy of the system are verified.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V228.11

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