Ellipsoidal acoustic emission patterns in basalt bio-epoxy laminates under different loading angles

The acoustic and mechanical behavior of basalt fiber-reinforced bio-epoxy laminates under different loading angles are investigated, with a focus on damage evolution description through acoustic emission (AE) monitoring. Laminates with different fiber orientations, quasi-isotropic [45/–45/0/90] 2S and angle-ply [45/–45] 4S were tested using an adapted Arcan fixture for simultaneous AE monitoring. A novel ellipsoidal visualization method is introduced to represent AE signal parameters, enabling a more intuitive interpretation of parameter magnitudes and trends. The study demonstrates that these ellipsoidal AE patterns enhance early damage detection and reveal shifts in AE responses corresponding to various stress states. The integration of AE monitoring with digital image correlation (DIC) and microscopy analysis provides complementary insights into failure mechanisms. Neural network classification of AE signals by normalized force regions confirms strong discriminative capability, particularly in the nonlinear loading phase where significant energy release events occur. The AE parameter transitions near peak load show consistent trends across both laminate types, with differences observed in the intensity of parameter shifts. The findings highlight the potential of AE monitoring as advanced diagnostics in sustainable fiber-reinforced composites. • The mechanical and acoustic responses of basalt bioepoxy laminates are studied. • A novel visualization approach using ellipsoidal AE patterns is introduced. • Different fiber layups influence the ellipsoidal acoustic response under loading. • Classification accuracy of AE signals depends on normalized force regions. • Acoustic peak loading transitions for different laminates and loadings are described.