Mixed-mode fracture toughness of co-cured and secondary bonded composite joints

In the present study, the mixed-mode fracture toughness of three composite joint systems (2 secondary bonded and 1 co-cured) was investigated. The two secondary bonded systems predominantly resulted in cohesive failure with occasional interlaminar failure during mixed-mode loading while the co-cured system failed adhesively. This was attributed to moisture stored in the prepreg being released during the co-cure process. The mode II toughness was...