Experimental investigation of the UV influence on the fatigue life of SLJ of CFRP/AL

The adhesively bonded joint in most of applications is subjected to a complex formation of loading system and environmental conditions. Application such as cars, boats and airplanes are real-life examples of these types of complex systems. Therefore, evaluating the joint performance in contradiction of these types of loading are essential steps to understand the joint behavior in different working conditions. The current study attempts to investigate the influence of ultraviolet and elevated temperature as well as other loading parameters such as mean load and frequency on the fatigue life and fracture modes of adhesively bonded single lap joint of CFRP and Aluminum. Therefore, single lap joint samples prepared and exposed to different ultraviolet levels and exposure durations, then tested with constant amplitude fatigue at different load levels and frequencies. The main outcomes of this study show a 90% reduction in the fatigue life by increasing fatigue loading from 2kN to 5kN and there is a 29% reduction by increasing frequency from 5Hz to 15Hz for the same load level. While UV exposure level shows only 3-5% reduction compared to 8% reduction for the elevated temperature influence on fatigue life.