Session: Virtual Presentations in Acoustics, Vibration, and Phononics

Paper Number: 94805

94805 - A Modified Time Reversal Based Probabilistic Imaging Method for Composite Plate Delamination Detection 

  Composite materials have been widely used in aerospace manufacturing because of their low mass, high specific strength, high specific stiffness, good vibration damping performance and good fatigue resistance. However, composite structures are susceptible to damage such as debonding and delamination due to various impacts, vibrations and other external loads. Therefore, it is crucial to regularly monitor composite structures in real-time during spacecraft service to ensure the safety and reliability of the structures. Ultrasonic guided wave is an effective means of monitoring the health of composite plate structures. Delamination, debonding and other damages of composite materials can be imaged and localized using ultrasonic guided wave signals and probabilistic imaging methods. However, due to the large damping of composite materials, the traditional probabilistic imaging method has the problem of low accuracy in damage localization. Therefore, in this paper, we propose a probabilistic imaging method based on a modified time reversal for damage localization and imaging of delamination damage. The modified timereversal method uses a piezoelectric sensor to receive a response guided wave signal. This response signal is firstly reversed in the time domain, and the reversed signal is recorded as the reference reemitting signal (RRS) of the structure. The RRS is then excited in the healthy state and the original excitation signal is reconstructed. In the damage state, the RRS is also used as the excitation signal, and a reconstruction signal can be obtained. The ratio of the energy of the reconstructed signals in the healthy state and the damaged state is used as the damage index. The damage index is used to locate and image the damage in combination with the existing probabilistic imaging methods. The proposed method was experimentally validated using a composite plate as a test piece and compared with the conventional method. First, a mass block was placed on the test piece as simulated delamination damage for the guided wave experiment and the location of the simulated damage was recorded, followed by low-velocity impact damage produced at the same location on the test piece using a drop hammer experiment. Comparing the localization accuracy of delamination damage between the traditional method and the modified time-reversal method, the results show that the modified time-reversal method can better localize and image the delamination damage of composite structures with higher localization accuracy and more sensitive to the damage,which verifies the feasibility and accuracy of the modified time reversal method in the localization of debonding damage of composite structures.

Presenting Author: YANG NAN Northwestern Polytechnical University

Presenting Author Biography: Name: Nanyang; gender: male; birth year: June 18, 2000; place of origin: Yan'an, Shaanxi; education: master's degree; work unit: Northwestern Polytechnic University, College of Astronautics

Authors:

YANG NAN Northwestern Polytechnical University
Maoling Yue Northwestern Polytechnical University
Haodong Fan Northwestern Polytechnical University
Fei Du Northwestern Polytechnical University
Lihua Wen Northwestern Polytechnical University
Chao Xu Northwestern Polytechnical University