【作者】 李媛；

【导师】 王召巴；

【作者基本信息】 中北大学 ， 信号与信息处理， 2008， 硕士

【摘要】 不等厚金属非金属复合构件以其优越的性能而广泛应用于航空航天领域,在使用过程中由于粘接界面脱粘而造成的事故往往是灾难性的,因此亟需对界面粘接质量进行准确的检测,以保证产品质量和使用安全。本文针对不等厚金属非金属复合构件的特点,提出了采用相控阵超声检测方式对该构件界面进行脱粘检测的方法。根据超声相控阵声束控制理论,建立了相位延时的数学模型,分析了不等厚构件的相控阵超声脱粘检测技术的可行性和优越性。通过研究超声阵列探头声场的指向性、时间延时精度和系统独立通道数对超声检测分辨率的影响,结合检测精度的要求,确定了相控阵探头和检测系统的具体参数,并利用该参数对多层介质的相控聚焦折射声场进行了仿真研究。分别采用普通聚焦探头和相控阵探头对不等厚试块进行了脱粘检测实验,采用软件延时技术对相控阵检测实验数据按聚焦规律进行合成,得到相控阵检测方式的C扫描灰度图和二值化图,并计算了脱粘区域的位置和面积,检测结果与普通聚焦探头相比,可以看出相控阵检测技术具有较高的检测分辨率和检测能力。总之,本论文的研究对于推动我国相控阵超声检测技术的发展具有重要意义。更多还原

【Abstract】 More and more not uniform thickness metal and nonmetallic compound components have been widely applied in aeronautics industry for their superior performances. The accident is often disastrous for adhesive interface debonding in the use process. So it is urgently needed to make an accurate detection for the adhesive quality of interface and insure the quality and use security of the products. According to the characteristic of the not uniform thickness compound component, phased array ultrasonic testing method is proposed to detect debonding on adhesive interface of this component.Based on the beam control theory, the phase delay mathematical model is established and the feasibility and the superiority of phased array ultrasonic debond testing technology on the not uniform thickness component is analyzed. The following analysis mainly focus on the influence of the sound field directivity of phased array probe, time delay precision and the system independent channels to the ultrasonic testing resolution. According to the test precision request, the specific experimental parameters of the system and probe is given. And then, focused refraction sound field of multi-layer mediums is simulated using the parameters. Debond testing experiment of not uniform thickness has carried on separately using the ordinary focused probe and the phased array probe. This paper synthesizes the experimental data of phased array probe making use of the focusing rule and the software time delay technology, then get the C-scan image and binary image to calculate the position and area of the debonding region. Comparing the testing results of phased array probe method and ordinary focused probe method, it can conclude that the phased array probe method has higher testing resolution and testing ability.Above all, the research findings above have great significance for the development of phased array ultrasonic testing technology.更多还原