Significantly enhanced joint strength and fatigue life of aerospace composite joints by using novel PEEK/PPS woven meshes as joining agent

Abstract

The development of advanced joining methods for carbon fibre/epoxy composites is critical for aerospace applications. Herein, advanced PEEK/PPS meshes were used to join carbon fibre/epoxy composites upon a novel co-curing process. The meshes were surface-activated upon an atmospheric plasma technique, which largely promoted the chemical interactions between the meshes and the composite epoxy matrix. The quasi-static joint strengths at both of 22 °C and 130 °C and fatigue loading resistance of the composite joints were evaluated using a single-lap joint test and the corresponding failure mechanisms were investigated. Encouragingly, the lap-shear strengths and fatigue resistance of the PEEK/PPS mesh-joined composites were larger than that of their counterparts bonded by an aerospace adhesive. Subsequent analysis on the failure surfaces proved PEEK/PPS fibre damage and epoxy crack were the main failure mechanisms of the PEEK/PPS co-cured joints. This work proposed a novel method for the production of robust aerospace joints by co-cure joining the composites using advanced PEEK/PPS meshes.