Effect of propagation distance on acoustic emission of carbon fiber/epoxy composites

Abstract

This study examined the change in acoustic emission as a function of measurement position of fiber-reinforced composites. Single-edge-notched carbon fiber/epoxy composites were prepared and tested under cyclic loading, with sensors located at specific distances from the end of the notch. Although the I b-value increased overall, the degree of increase significantly varied with position and acoustic emission frequency. Notably, the proportion of acoustic emission signals for each failure mode varied due to a high attenuation rate at high frequencies, which increased the I b-value. Accordingly, the high-frequency fiber-failure signals significantly affected the I b-value. This study focused on the importance of analyzing acoustic emission signals by considering the crack location and frequency-dependent attenuation rate. We concluded that an acoustic emission sensor should be located 20–40 mm from the crack location for woven carbon fiber/epoxy composites.

Investigation of Ib-Values for Determining Fracture Modes in Fiber-Reinforced Composite Materials by Acoustic Emission

“…The b-value analysis tracks the amplitude trend of AE signals, showing a lower value at a severe damage state. To the authors' knowledge, the application of b-value analysis in composite materials is rare, and is a first in our research group [28][29][30][31]. In previous studies in our group, we revealed a specific frequency AE signal range for each fracture mode, and the b-value analysis is feasible in composite materials.…”

Study on the effect of different angles on the propagation characteristics of acoustic emission signals in wood

“…The AE signal is more susceptible to variations in the AE signal during long-distance propagation as the AE signal is normally attenuated by the material itself. 42 , 43 However, because wood belongs to anisotropic material, the kinetic energy change rules of the 3 sensors far away were inconsistent. To clearly explain this change, as shown in Figure 5 , slice dyeing was performed on the used Zelkova schneideriana specimen, and the internal structure of wood was observed by electron microscope.…”

Three-point bending damage detection of GFRP composites doped with graphene oxide by acoustic emission technology

“… 16 used the b-value to describe the statistical characteristics of signal amplitude, and then used the c-value and frequency fluctuations to characterize the frequency features of the signal, thereby analyzing the damage evolution process in GFRP composites. In other studies, 17 , 18 b-values and improved b-values (Ib-values, which are calculated based on the mean and standard deviation of the AE signal amplitude distribution) have been employed in AE damage evolution analysis for damage detection in composite materials. Wang et al.…”