Cumulative acoustic emission energy for damage detection in composites reinforced by carbon fibers within low-cycle fatigue regime at various displacement amplitudes and rates

Abstract

In the present article, acoustic emission signals were utilized to predict the damage in polymer matrix composites, reinforced by carbon fibers, in the low-cycle fatigue regime. Displacement-controlled fatigue tests were performed on open-hole samples, under different conditions, at various displacement amplitudes of 5.5, 6.0, 6.5 and 7.0 mm and also under various displacement rates of 25, 50, 100 and 200 mm/min. After acquiring acoustic emission signals during cycles, two characteristic parameters were used, including the energy and the cumulative energy. Obtained results implied that the energy parameter of acoustic emission signals could be used only for the macroscopic damage, occurring at more than 65% of normalized fatigue cycles under different test conditions. However, the cumulative energy could properly predict both microscopic and macroscopic defects, at least two failure types, including matrix cracking at first cycles and the fiber breakage at last cycles. Besides, scanning electron microscopy images proved initially such claims under all loading conditions.

Enhancing the acoustic emission technique using fuzzy artificial bee colony-based deep learning for characterizing selective laser melted AlSi10Mg specimens

“…The cumulative energy is one of the AE parameters widely and effectively used to characterize damage in materials (Azadi et al, 2021;Qiu et al, 2019;Tian et al, 2021;Yu et al, 2018). It is defined as the total amount of energy of the acoustic event recorded over the time range from t 0 to t i .…”

Analysis of friction‐related acoustic emission in bolted joint structures

“…waves generated in solids due to the release of strain energy by a variety of mechanisms. [4][5][6] It has been shown in previous studies 7 that clear AE signals will be generated during the reciprocating friction of the bolted joint interface. Finding the relationship between the frictional slip features and the AE signal characteristics under different bolt preloads can lay the foundation for using the AE techniques to monitor the pretightening state of bolted joints, which has attracted much attention in recent years.…”

“…Therefore, it is essential to find a way to monitor the contact state of a bolted joint on time and handle it adeptly. Acoustic emission (AE) is a phenomenon related to stress waves generated in solids due to the release of strain energy by a variety of mechanisms 4–6 . It has been shown in previous studies 7 that clear AE signals will be generated during the reciprocating friction of the bolted joint interface.…”

Dynamic Elastic Modulus Variability in Anisotropic and Isotropic Materials: Comparison by Acoustic Emission

“…It is well known how the AE can find damage occurrences and crack propagation in composite materials [7][8][9][10][11][12][13], as so as the procedures to use the nondestructive technique [14][15][16] for evaluation of damage propagation, for numerous composites and plate structures [9,11,17,18]. However, the literature presents scarce works on industrialized lamination processes evaluation, where the layering presents unusual directions like FW, the pultrusion, sheet molding compound (SMC), or automated fiber placement (AFP), which use unidirectional or bidirectional fabrics, or prepreg [19].…”