The effects of manufacturing-induced and in-service related bonding quality reduction on the mode-I fracture toughness of composite bonded joints for aeronautical use

摘要: Abstract The scope of the present work is to investigate possible effects manufacturing and in-service induced reduction bonding quality on mechanical performance composite bonded joints appearing in aeronautical applications, due defects that cannot be detected sufficiently by means conventional NDT. To this end, an experimental program has been conducted measure mode-I interlaminar fracture toughness adhesively CFRP laminates. Five different representative scenarios have considered; namely, poor curing adhesive, release agent contamination moisture uptake substrates, which may occur during joints, as well Skydrol thermal degradation are related life could affect repair. Eight specimens for each scenario were tested. assess scenario, results compared with relative measurements taken from a set reference specimens. Prior testing, NDT techniques, ultrasound C-scan X-ray tests bondline. All considered study found effect joints. It was also shown NDT, such ultrasonic inspection, not capable detect resulting specific being responsible joint’s performance.