An investigation on static and fatigue life evaluation of grooved adhesively bonded T-joints

Adhesively bonded joints with T-shaped configurations are widely used in bonded components of engineering structures used in industries such as automotive, aircraft, and marine. In this paper, static strength and fatigue life of two T-joint configurations of flat and grooved types were evaluated. For this purpose, firstly, the effect of the specimen configuration of the bonded T-joints on the stress field has been calculated using the finite element method. For this purpose, a three-dimensional elastoplastic model is used for simulation. Then, static failure load of these joint types was examined under four loading rates of 1, 10, 50, and 100 mm/min. Also, fatigue tests were performed under maximum fatigue loads of 40%, 60% and 80% of average static failure loads. Results indicated that the average static failure load of grooved specimens was 37.3%, 26.5%, 14.4%, and 9.3% higher than that of the flat type T-joints under 1, 10, 50, and 100 mm/min loading rates, respectively. Moreover, fatigue life cycles of grooved T-joints were 40.2%, 25.3%, and 11.6% longer than that of the flat bonded specimens under 40%, 60%, and 80% maximum fatigue loads, respectively. It was also concluded that, under high fatigue loads, the groove effect can be ignored on improving the fatigue life.