Faculty of Mechanical Engineering and Design, Kaunas University of Technology, Studentu str., 56-321 Kaunas, Lithuania.
Institute of Mechatronics, Kaunas University of Technology, Studentu str., 56-005 Kaunas, Lithuania.
Sensors (Basel). 2021 Jan 2;21(1):253. doi: 10.3390/s21010253.
This paper focuses on the investigation of the diagnostic system for health monitoring and defects, detecting in composite structures using a piezoelectric sensor. A major overview of structural defects in composite materials that have an influence on product performance as well as material strength is presented. Particularly, the proposed diagnostic (health monitoring) system enables to monitor the composite material plate defects during the exploitation in real-time. The investigated health monitoring system can indicate the material structure defects when the periodic test input signal is provided to excite the plate. Especially, the diagnostic system is useful when the defect placement is hard to be identified. In this work, several various numerical and experimental studies were carried out. Particularly, during the first study, the piezoelectric transducer was used to produce mechanical excitation to the composite plate when the impact response is measured with another piezoelectric sensor. The second study focuses on the defect identification algorithms of the raw hologram data consisting of the recorded oscillation modes of the affected composite plate. The main paper results obtained in both studies enable us to determine whether the composite material is characterized by mechanical defects occurring during the response to the periodic excitation. In case of damage, the observed response amplitude was decreased by 70%. Finally, using the time-domain experimental results, the frequency response functions (FRFs) are applied to damage detection assessment and to obtain extra damage information.
本文重点研究了使用压电传感器在复合材料中进行健康监测和缺陷检测的诊断系统。本文对复合材料中的结构缺陷进行了全面概述，这些缺陷会影响产品性能和材料强度。特别是，所提出的诊断（健康监测）系统能够在复合材料板的实际使用过程中实时监测缺陷。当周期性测试输入信号被提供以激励板时，所研究的健康监测系统可以指示材料结构缺陷。特别是，当缺陷位置难以识别时，该诊断系统非常有用。在这项工作中，进行了几项数值和实验研究。特别是，在第一项研究中，当使用另一个压电传感器测量冲击响应时，压电换能器用于对复合材料板产生机械激励。第二项研究侧重于原始全息数据的缺陷识别算法，该算法由受影响的复合材料板的记录振动模式组成。在这两项研究中获得的主要结果使我们能够确定复合材料是否存在对周期性激励做出响应时出现的机械缺陷。如果有损伤，观察到的响应幅度会降低 70%。最后，使用时域实验结果，将频响函数（FRF）应用于损伤检测评估，并获取额外的损伤信息。
