Damage analysis of combined continuous and discontinuous thin‐ply carbon/glass hybrid composite using acoustic emission

Abstract Thin‐ply hybrid composite is an attractive technology for realizing high‐performance ductile composites (carbon and glass). However, the continuous carbon (CC) layers are limited to a thickness that can only emit small fracture energies to achieve pseudo‐ductility, compromising the mechanical performance of the laminates due to the low carbon/glass ratio. To solve this problem, four different lay‐up architectures of partially discontinuous carbon (DC) and angled carbon layers were coupled with continuous glass and carbon to increase the carbon/glass ratio maintaining pseudo‐ductility and improve mechanical properties. When under tensile loading, sandwiched DC layers with CC layers (H212) can achieve pseudo‐ductility with good mechanical properties compared to a sample with similar carbon layer thickness but with CC sandwiched by DC layers (H412). An improvement of 13% on the modulus and 2% on the yield strength is registered. Besides, acoustic emission (AE) analysis and sentry function are used to monitor the behavior of the respective damage mechanisms in the hybrid composites. The AE procedure used clustered the carbon and glass fiber breakages separately. Consequently, the sentry function analysis shows the damage mechanisms damage progression causing pseudo‐ductility.