Smagulova Damira, Mazeika Liudas, Jasiuniene Elena
Ultrasound Research Institute, Kaunas University of Technology, K. Barsausko Str. 59, LT-51423 Kaunas, Lithuania.
Department of Electronics Engineering, Kaunas University of Technology, Studentu St. 50, LT-51368 Kaunas, Lithuania.
Sensors (Basel). 2021 Apr 27;21(9):3048. doi: 10.3390/s21093048.
Adhesively bonded dissimilar materials have attracted high interest in the aerospace and automotive industries due to their ability to provide superior structural characteristics and reduce the weight for energy savings. This work focuses on the improvement of disbond-type defect detectability using the immersion pulse-echo ultrasonic technique and an advanced post-processing algorithm. Despite the extensive work done for investigation, it is still challenging to locate such defects in dissimilar material joints due to the large differences in the properties of metals and composites as well as the multi-layered structure of the component. The objective of this work is to improve the detectability of defects in adhesively bonded aluminum and carbon fiber-reinforced plastic (CFRP) by the development of an advanced post-processing algorithm. It was determined that an analysis of multiple reflections has a high potential to improve detectability according to results received by inspection simulations and the evaluation of boundary characteristics. The impact of a highly influential parameter such as the sample curvature can be eliminated by the alignment of arrival time of signals reflected from the sample. The processing algorithm for the improvement of disbond detectability was developed based on time alignment followed by selection of the time intervals with a significant amplitude change of the signals reflected from defective and defect-free areas and shows significant improvement of disbond detectability.
由于具有提供卓越结构特性和减轻重量以实现节能的能力，粘结的异种材料在航空航天和汽车工业中引起了高度关注。这项工作着重于利用浸入式脉冲回波超声技术和先进的后处理算法来提高脱粘型缺陷的可检测性。尽管已经开展了大量的研究工作，但由于金属和复合材料的性能差异很大以及部件的多层结构，在异种材料接头中定位此类缺陷仍然具有挑战性。这项工作的目的是通过开发一种先进的后处理算法来提高粘结铝和碳纤维增强塑料（CFRP）中缺陷的可检测性。根据检测模拟结果和边界特性评估，确定对多次反射进行分析具有提高可检测性的巨大潜力。通过对齐从样品反射的信号的到达时间，可以消除诸如样品曲率等极具影响力的参数的影响。基于时间对齐，随后选择有缺陷区域和无缺陷区域反射信号幅度有显著变化的时间间隔，开发了用于提高脱粘可检测性的处理算法，该算法显著提高了脱粘可检测性。
