Failure analysis of adhesively bonded composite joints using 3D BEM formulation

The use of adhesive bonding in the industry has been increasing significantly in recent years, especially in technical applications, e.g., bonded repairs and doublers in aircraft structures. This growth is due to its advantages when compared with traditional joining methods. The main advantages of adhesively bonded joints are: i) reduced average stress and stress concentration, ii) high fatigue strength and iii) the greater capacity for shock absorption and vibration. In this paper, adhesively bonded composite joints are analyzed using the elastostatic 3D boundary element method (BEM) formulation with a fundamental solution based on double Fourier series and the multidomain algorithm. Comparisons are carried out with linear and non-linear analytical models of the stress distributions, such as Volkersen, Goland and Reissner, Hart-Smith and Ojalvo and Eidinoff. The adhesive failure is evaluated using a generalized energy failure criterion that considers the interaction between shear and cleavage modes. Results obtained by this criterion are compared with the main failure criteria for bonded joints found in literature and experimental data.