Papanaboina Mastan Raja, Jasiuniene Elena, Žukauskas Egidijus, Mažeika Liudas
Prof. K. Baršauskas Ultrasound Research Insititute, Kaunas University of Technology, K. Baršausko St. 59, LT-51423 Kaunas, Lithuania.
Department of Electronics Engineering, Kaunas University of Technology, Studentu St. 50, LT-51368 Kaunas, Lithuania.
Materials (Basel). 2022 May 11;15(10):3466. doi: 10.3390/ma15103466.
Multilayered carbon fiber-reinforced polymers (CFRP) are increasingly used in aircraft components because of their superior mechanical properties. However, composite materials are vulnerable to impact loads, resulting in delamination-type damage which, if unnoticed, could lead to catastrophic structural failure. The objective of this research was to investigate possibilities to improve damage detection and the localization using signal processing methods. Numerical modeling using the semi-analytical finite element (SAFE) method was performed to obtain guided wave dispersion curves and to perform modal analysis. From the modal analysis, A0 mode for inspection of the composite with delamination type defects was selected. From the numerical simulation, A0 mode interaction with delamination along the longitudinal direction was analyzed and the location of the defect was estimated by measuring the time of flight (ToF) of the signal using Hilbert transform (HT) and continuous wavelet transform (CWT). The CWT has shown better results in estimating the delamination location compared with HT. The depth of delamination was characterized in the frequency domain by comparing the amplitude of the A0 mode. Inverse fast Fourier transform (IFFT) is recommended to reconstruct the reflected and transmitted modes for better damage detection and to reduce the complexity of signal interpretation.
多层碳纤维增强聚合物（CFRP）因其优异的机械性能而越来越多地用于飞机部件。然而，复合材料易受冲击载荷影响，会导致分层型损伤，如果未被发现，可能会导致灾难性的结构失效。本研究的目的是探讨使用信号处理方法改善损伤检测和定位的可能性。采用半解析有限元（SAFE）方法进行数值建模，以获得导波频散曲线并进行模态分析。通过模态分析，选择用于检测具有分层型缺陷复合材料的A0模式。从数值模拟中，分析了A0模式与沿纵向分层的相互作用，并使用希尔伯特变换（HT）和连续小波变换（CWT）通过测量信号的飞行时间（ToF）来估计缺陷的位置。与HT相比，CWT在估计分层位置方面显示出更好的结果。通过比较A0模式的幅度在频域中表征分层深度。建议使用快速傅里叶逆变换（IFFT）来重建反射和透射模式，以实现更好的损伤检测并降低信号解释的复杂性。
