Strength prediction of a single lap joint under impact using meshless methods

Abstract

The use of adhesive joints in structures subjected to dynamic loads, such as wind turbines and cars, makes it important to study them under those conditions. Numerical models are an integral part of that. Commonly the Finite Element Method (FEM) is used, but meshless methods can be an interesting alternative. These models do not require elements, and as such they can model complex geometries more easily. The current work aims at performing a first study on adhesive joints under impact using a meshless method, the Radial Point Interpolation Method (RPIM). Since the strength prediction of adhesive joints is also an important field and because the commonly used Cohesive Zone Models (CZM) have some limitations, like the use of special cohesive elements, this work also aims to expand the use of the ISSF criterion to impact conditions. The results show that the RPIM can be used in this type of problem without numerical difficulties, and the ISSF gives acceptable strength predictions, with errors between 30.5% and 13.5%.

Adhesive bonding is a joining technique that offers some advantages, when compared to other common joining techniques, like bolting or riveting. One of those advantages is that adhesive joints are generally lighter than the alternatives, which is very important in the search for more efficient modes of transportation since lighter vehicles consume less energy. Given the interest in the use of adhesive joints, it is important to study their behaviour under different conditions. Currently, the static behaviour of adhesive joints is very well documented, with many research works dedicated to it. However, the number of publications on their dynamic behaviour is still scarce, with only a few works dedicated to fatigue, impact and free vibrations. Additionally, the use of meshless methods to study adhesive joints is also currently mostly limited to static analysis, and even in that case it is still very incipient. Therefore, this work aims at extending the use of meshless methods to the dynamic analysis of adhesive joints, to help in the advancement of both fields.