Session: Virtual Presentations in Acoustics, Vibration, and Phononics

Paper Number: 95421

95421 - Quantitative Detection of Delaminations in CFRP Composite Plate by Spatial-Frequency-Wavenumber Analysis Based on Laser Ultrasonic Guided Waves 

QUANTITATIVE DETECTION OF DELAMINATIONS IN CFRP COMPOSITE PLATE BY SPATIAL-FREQUENCY-WAVENUMBER ANALYSIS BASED ON LASER ULTRASONIC GUIDED WAVES

Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China

*Corresponding author, E-mail: liuzenghua@bjut.edu.cn; Tel.: 8610-67392377.

Carbon fiber composite(CFRP) is widely used in aerospace, automobile, sports fitness equipment and other fields due to its high stiffness and strength. However, in the manufacturing process, defects such as pores, cracks, debonding and lamination are easy to form in the internal and surface of carbon fiber composite. Therefore, to comprehensively quantitative assessment of location and two-dimensional (2D) contour shape of lamination defect in CFRP plates, a Lamb wave spatial frequency wavenumber imaging method based on laser ultrasonic full-wavefield scanning inspection is proposed in this paper. Simulation and experimental study are carried out in this paper. Mode selection has great influence on imaging accuracy.A₀ mode is commonly used, because of its high sensitivity to thickness variations.In this study,a three-period 250kHz Tone-burst signal modulated by Hanning window was selected to generate A₀ mode. Frequency domain filtering and short-space Fourier transform were performed on the received wavefield signal to obtain a distribution image of Lamb wave spatial wavenumber. An image segmentation algorithm is adopted to extract the contour of the defect edge profile. At the same time, the Lamb wave dispersion relation in CFRP plate is analyzed, and the lamination defect location is calculated based on this relationship.A three-dimensional finite element model is established by Matlab and ABAQUS commercial software. The simulation results show that the locations of the lamination defects and the two-dimensional contour shape are close to the actual value. An experimental system is established, in which the excitation signal is generated by the function generator, the amplitude is amplified by the power amplifier, the piezoelectric ceramic sensor is used as the transmitter, the dual-wave mixing interferometer is used as the receiver to scan point by point in the wavefield, and the LabVIEW host computer software is used to automatically receive.The methodology was verified on T300/QY8911 carbon fiber/epoxy resin composite laminates of 2.24mm thickness. Laminate has 16 layers, 0.14mm each layer, and the stacking mode is [(0/45/90/-45)₂]_s. The circular delamination defect with a diameter of 30mm is located between 4 and 5 layers. The experimental results are in good agreement with the simulation results. Based on the above analysis, this method can realize the comprehensive quantitative evaluation of the location and contour of delamination defects in carbon fiber composites.

Keywords: Nondestructive evaluation, CFRP plate, Lamb waves wavefield, Lamination defect, Spatial-frequency-wavenumber analysis.

Presenting Author: xiaoyu Liu Beijing University of Technology

Presenting Author Biography: Xiaoyu Liu received BACHELOR's degree in mechanical design and manufacturing and automation from Fujian university of Technology,Fujian,China,in 2016.She is now a postgraduate student at Beijing University of Technology.Her main research interests include ultrasonic guided wave testing technique and material property characterization method.

Authors:

Zenghua Liu Beijing University of Technology
xiaoyu Liu Beijing University of Technology
Jiuzhou Tian Beijing university of techonology