An asymptotic solution for evaluation of stresses in balanced and unbalanced adhesively bonded joints

Adhesively bonding is one of the most commonly and widely used joining methods in various engineering applications. Many fiber-reinforced plastic (FRP) structural components nowadays are joined by adhesives. As a result many researchers have expended considerable effort in developing analytical solutions and computational procedures to assess the stress distribution in such joints. Most of the works however have considered joints that are balanced, formed with a thin layer of adhesive, mainly useful in characterizing joints in aerospace structural applications. However, in many applications, especially in marine and civil infrastructure applications, the adhesive layers are relatively thick, and the joints are usually unbalanced. Therefore seeking an accurate and robust analytical solution for characterizing such adhesively bonded joints is desirable. In this paper, an analytical closed-form solution is developed based on the asymptotic method, using the assumptions laid out by earlier researchers (e.g., Goland and Reissner and others). The solution is capable of characterizing the stress distribution in balanced and unbalanced joints with a thin or thick layer of adhesive. The integrity of the solution is verified by the finite element method.