Investigation of low-cycle fatigue in adhesively-bonded single-lap joints

Adhesively bonded joints are used as an alternative to classical mechanical joining methods, e.g., bolts, rivets, welding, and soldering, due to their advantages such as high strength, uniform stress distribution, and good fatigue resistance. These adhesively bonded joints are becoming more and more important, especially in fields where weight is critical, such as aviation and aerospace. Adhesively bonded joints are preferred because they offer highly reliable connections. In the present study, the low-cycle fatigue of materials joined together as adhesively bonded single-lap joints were investigated experimentally and numerically. Joints of aluminum and steel samples were subjected to variable loads that were lower than the experimentally obtained average breaking loads, and the number of cycles was determined. As a result, the fatigue life of adhesively bonded single-lap stainless steel samples was observed to be higher than that of aluminum samples. In addition, it was also observed that smudging adhesive around the endpoints of the joint significantly increased the fatigue life of steel samples.