Static and Fatigue Behaviour of Aluminium Bonded Joints

An experimental investigation into the effects of surface roughness and environmental conditions into the static and fatigue behaviour of bonded aluminium joints is performed. Four levels of surface roughness are used and three environmental conditions ('dry', 21 days at 50 degreesC, 50% humidity and 42 days at 50 degreesC, 50% humidity) are used. It is concluded that the adherents' surface roughness affects both static and fatigue strength, as well as the failure mode. There is an optimum value of the roughness, above which there is a decrease on the strength. The presence of humidity and high temperatures reduces marginally the static strength of the joint, but, for the humidity and temperatures used here, improves the fatigue behaviour of the joint.