航空器蒙皮结构缺陷检测电阻抗成像系统设计

Design of electrical impedance tomography system for aircraft skin structure defects

为了便于检测航空器蒙皮结构缺陷状况,弥补人工检测的不足,设计了一套16电极的电阻抗成像系统。该系统利用正弦信号,以相对激励模式刺激样品,用测量值解调信息对比由前向运算求得的相对参考幅值,基于开源软件Octave和软件包EIDORS,利用图像重构算法得到蒙皮结构的电导率分布图像,以其电导率变化趋势表征蒙皮结构缺陷状况。成像实验选用了航空器常用板材2024 T-3铝合金板材作为样品,并利用PE等评价指标对重建图像质量进行了评价,结果表明利用该系统可以测量到样品由于缺损引起的电导率变化,故该系统可以有效检测金属材料蒙皮结构缺陷。

A 16-electrode electrical impedance imaging system was designed to facilitate the detection of defects in the aircraft skin structure and to make up for the lack of manual testing. The sinusoidal signal was used to stimulate the sample in a relative excitation mode. Compared with the relative reference amplitude obtained by forward operation, measured value demodulation information and the image reconstruction algorithm were used to obtain the conductivity distribution image of the skin structure based on open source software Octave and package EIDORS. So the defect status of skinning structure is characterized by the changing trend of its conductivity. Commonly used material 2024 T-3 aluminum alloy plate in aviation manufacturing industry was selected as a sample for real-time resistance anti-imaging experiments, and the reconstruction image quality is evaluated by PE and other evaluation indicators. The results show that the change of conductivity caused by defect of the sample can be measured by using the system and the system can effectively monitor the structural defects of the metal skin.