Ultrasonic Guided Wave Testing on Cross-Ply Composite Laminate: An Empirical Study

Abstract

Structural health monitoring comprises a set of techniques to detect defects appearing in structures. One of the most viable techniques is based on the guided ultrasonic wave test (UGWT), which consists of emitting waves throughout the structure, acquiring the emitted waves with various sensors, and processing the waves to detect changes in the structure. The UGWT of layered composite structures is challenging due to the anisotropic wave propagation characteristics of such structures and to the high signal attenuation that the waves experience. Hence, very low amplitude signals that are hard to distinguish from noise are typically recovered. This paper analyzes the propagation of guided waves along a cross-ply composite laminate following an empirical methodology. The research compares several implementations for UGWT with piezoelectric wafer active sensors. The reference for comparison is set on a basic mode, which considers the application of nominal voltage to a single sensor. The attenuation and spreading of the waves in several directions are compared when more energy is applied to the monitored structure. In addition, delayed multiple emission is also considered in multisensor tests. The goal of all the UGWT configurations is to transmit more energy to the structure such that the echoes of the emission are of greater amplitude and they ease the signal processing. The study is focused on the realization of viable monitoring systems for aeronautical composite made structures.

Structural Health Monitoring Using Ultrasonic Guided-Waves and the Degree of Health Index

“…The damage index is based on pattern matching using fuzzy logic fundamentals, which provide it with robustness against measurement uncertainties. The adoption of the transmission beamforming technique for SHM entails the collection of large amount of data [ 46 , 51 ]. This allows a more robust damage detection, providing redundancy and ensuring an accurate monitoring in the event of hardware failure, for example, sensor malfunction.…”

Assessment of damage in composites using static component generation of ultrasonic guided waves

“…There has been increasing interest in studying the cost effective and time efficient techniques for NDT&E of composites based on the ultrasonic waves. In particular, the characterization of composites using ultrasonic guided waves (GWs) has gained significant attention in the past decades [7,8]. The use of GWs has proven to be an effective and efficient means for inspecting composite laminates [9].…”