Experimental investigation of stacking interface on mode II interlaminar behaviour of self-healable vitrimeric CFRP

With the extensive research on ester -exchanged vitrimer, laminates utilizing vitrimer as matrix have garnered increasing attention due to their healability for achieving long-term durability of the composite structure. However, current research on the healing of mode II delamination for vitrimeric CFRP (vCFRP) laminates remains notably limited. In this study, the ENF tests were implemented to acquire load -displacement curves of eight typical vCFRP laminates with various interfaces. The results indicated a pronounced impact of the stacking interface on the fracture toughness values, the R -curves, fiber bridging effect, and crack growth behaviours. The continuous 0 degrees fiber hindered the upward migration for the laminates with 0 degrees //theta degrees interface, while the discontinuous theta degrees 1 fabric had a lower in -plane strength and were more prone to cracking for the laminates with theta degrees 1 //theta degrees 2 interface. Subsequently, the healing efficiencies of specimens were characterized. The healed laminates undergone three shear delamination damages could still achieve a substantial recovery of about 76.33 %.