Study of tensile-tensile fatigue behavior of patch repaired carbon-glass hybrid composite

Aside from the numerous benefits of fiber-reinforced composites, these materials are prone to impact damage, reducing structure's strength and stiffness. In this case, composite repair offers a unique and cost-effective alternative for restoring structural integrity. In this work, post-repair performance of the carbon-glass hybrid composite is investigated in tensile-tensile fatigue loading environments. To analyze repair performance, two distinct parent configurations (H1:G2C4G2 and H2: C2G4C2) and four patch configurations (Repaired1: CG3, Repaired2: C2G2, and Repaired3: C3G, Repaired4: G4) are considered. The digital image correlation approach and acoustic emission sensors are used to examine the specimens' damage behavior. First, fatigue tests are performed for drilled specimens, the H2 specimen dissipate more energy during fatigue cycles than the drilled H1 specimen due to the early damage initiation in the H2 specimen. The repaired specimens with the parent H1 laminate performed better than the parent H2 laminate. The Repaired4 configuration with H1 parent laminate sustained 300% higher cycles than the drilled H1 without final failure, which showed the highest fatigue life among all the repaired configurations. Patches with fewer glass plies outperformed all hybrid patches. The damage events recorded by acoustic emission sensors indicate that delamination damage considerably impacts fatigue life.Highlights Post-repair fatigue behavior of carbon-glass hybrid composite was examined. Effect of parent laminate stacking sequence and patch configuration was studied. Fatigue performance was analyzed using the damage mode and energy loss factor. Digital image correlation technique and acoustic emission sensors were utilized. Delamination damage showed a higher impact on the fatigue life of the sample. Analysis of fatigue performance of damaged and repaired carbon-glass hybrid composite. image