Efficient Stress Analysis of Adhesively Bonded Joints by Finite Element Techniques

The paper documents ongoing research on the field of stress calculations in the adhesive layer of bonded joints and bonded structures. Aim of the research is to develop simple, general, portable, efficient and accurate finite element techniques for adhesive stress analysis and strength assessment of the joint. Among four methods envisioned, two methods are presented for 2D configurations and applied to a reference single-lap configuration. In both methods, the adherends are described by means of beam elements and the adhesive layer by a single string of plane-stress solid elements. The plane-stress elements have either the original thickness of the true adhesive layer or an expanded thickness up to the offset between adherends. Beams and plane-stress elements are connected by standard constraining techniques (tied mesh) offered by the package employed (ABAQUS). The stress results provided by the two methods are compared step by step with the predictions of analytical models retrieved from the literature and with the outcome of a full, computationally-intensive finite element model using solid plane-stress elements for both adhesive and adherends. The simplified method using a single layer of plane-stress elements with the same thickness and properties as the true adhesive layer provides very promising results in terms of stress accuracy and computational efficiency.