Non-linear investigation of overlap length effect on torsional capacity of tubular adhesively bonded joints

Adhesively bonded joints are widely used due to their ease of fabrication, maintenance and controllable stress distribution in the overlap region. There are extensive investigations in literature that characterize the behavior of bonded joints with different geometries and materials (i.e. isotropic and anisotropic) and subject to various loading conditions. Although much work has been done on this subject, investigation into the effect of the material non-linearity on joint behavior is scarce. Our earlier experimental and numerical works revealed interesting, yet unpredictable results. This paper aims at addressing some of the ambiguities experienced in our previous work. The paper presents the development of numerical models of tubular joints made of composite/metallic adherends, subject to high strain fields as a result of torsional loading, with the consideration of both material and geometrical non-linearity. The results showed that the non-linearity of the adherends’ materials at high strain magnitudes played an important role in governing the bond efficiency in joints whose overlap length surpassed a certain limit. It was also realized that joints performance was also significantly affected by fabrication related issues.