Enhancing strength and stiffness of composite joint through co-cure technique

The co-cure manufacturing process effectively merges the various composites parts in wings, fuselage, and frames in aerospace applications. The current study investigates the combined effects of co-cure manufacturing technique and multi-wall carbon nanotubes (MWCNTs) reinforcement on shear strength and fundamental natural frequency of single lap joints (SLJs). In continuation, results were compared with SLJs fabricated through cobonding and secondary bonding. Shear analysis affirmed that SLJs prepared using co-cure manufacturing technique along with 0.25 wt% MWCNT addition increased the shear strength by 104.25 %, 88.2 % while comparing with co-bonded and secondary bonded joints, respectively. The scanning electron microscopy (SEM) and atomic force microscopy (AFM) indicated uniform dispersion of 0.25 wt% MWCNTs increased the joint strength, deviated crack propagation path, formation of shear bands and uneven surfaces in the adhesive layer. The experimental modal analysis revealed that 0.25 wt% CNT addition with co-cured manufacturing technique enhanced fundamental natural frequency, whereas higher wt.% MWCNT addition increased the damping factor of lap joint due to nanoparticle agglomeration increased the interaction between adhesive and adherend.