Numerical analysis of edge effects in adhesively-bonded assemblies application to the determination of the adhesive behaviour

This paper presents contributions of numerical modelling for the optimization of adhesively-bonded assemblies for marine and underwater applications. The experimental and numerical analyses of the mechanical behaviour of bonded joints are particularly made difficult by the stress singularities due to edge effects. Therefore, to analyse the behaviour of the adhesive in an assembly, experimental fixtures which strongly limit edge effects must be designed in order to obtain reliable data. Different finite element analyses, under the assumption of elastic behaviour of the constituents, have highlighted the influence of two parameters: the geometry of the substrate close to the adhesive joint and the local geometry of the joint near the edge. The numerical results have been confirmed through experimental tests. Moreover, numerical simulations taking into account the non-linear behaviour of the adhesive give more information about the way an adhesive behaves in an assembly. An improvement is proposed in order to nearly cancel out the solicitation of the adhesive near the free edge of the joint.