Experimental identification of static and dynamic strength of epoxy based adhesives in high thickness joints

Epoxy based adhesives already have a long history in structural joining. Commonly with this type of adhesive, the bond layer is thin. However, as the thickness of a joint increases (e.g. over 10 mm), its structural properties may alter very much. In such a case, both the interfacial strength and the intrinsic adhesive strength need to be verified in static and dynamic conditions. This research work identifies joint strength using a mainly experimental procedure. Coupons are subjected both to quasi-static and fatigue loads at different conditions. In order to take into account the variability present in the experimental campaign, a probabilistic approach identifies the most appropriate failure criterion. The strength prediction method considers a statistical size effect in the strength of the material by considering not only the magnitude of the stress distributions, but also the volume over which these act. Both quasi-static and fatigue results are analysed using probabilistic tools, leading to quite fine results.