Standard finite element techniques for efficient stress analysis of adhesive joints

The paper documents ongoing research in the field of stress analysis of adhesive bonded joints and aimsat developing efficient and accurate finite element techniques for the simplified calculation of adhesivestresses. Goal of the research is to avoid the major limitations of existing methods, in particular theirdependency on special elements or procedures not supported by general purpose analysis packages.Two simplified computational methods, relying on standard modelling tools and regular finite elementsare explored and compared with the outcome of theoretical solutions retrieved from the literature andwith the results of full, computationally intensive, finite element analyses. Both methods reproduce theadherends by means of structural elements (beams or plates) and the adhesive by a single layer of solidelements (plane-stress or bricks). The difference between the two methods resides in the thickness andin the elastic properties given to the adhesive layer. In one case, the adhesive thickness is extended up tothe midplane of the adherends and its elastic modulus is proportionally increased. In the other case, theadhesive layer is maintained at its true properties and the connection to the adherends is enforced bystandard kinematic constraints. The benchmark analyses start from 2D single lap joints and are thenextended to 3D configurations, including a wall-bonded square bracket undergoing cantilever loading.One of the two simplified methods investigated provides accurate results with minimal computationaleffort for both 2D and 3D configurations.