Influence of the Resin Layer Thickness at the Interface of Hybrid Metal-composite Co-cured Joints

As discussed in literature, the accurate analysis of the modern co-cured joints between composite materials or between a metal and a composite material (hybrid joints) is complicated by the influence of the interface resin layer on the interface singular stress field. In such joints, in fact, there is not a proper adhesive layer and the thickness of the resin layer, that plays the role of the adhesive, is not constant due to the presence of the reinforcing fibers in the composite adherent. For this reason several authors assume that a generic co-cured joint can not be studied as a simple bi-material joint, without considering the particular characteristics of the actual resin layer. This problem is also involved into the development of reliable design methods able to give accurate predictions of the joint efficiency. In this work, by theoretical analyses performed by using the Lekhnitskii theory, numerical simulations carried out by means of the boundary element method and experimental investigations based on the combined use of the generalized Dundurs parameters and digital photoelasticity, the influence of the resin layer on the singular stress field at the interface of a generic hybrid metal-composite joint, has been investigated.© 2011 Published by Elsevier Ltd. Selection and peer-review under responsibility of ICM11