Mixed-mode Cohesive Properties of a Thin Adhesive Layer

Abstract

It is crucial to precisely forecast the strength and fracture properties of adhesive structures while designing them (critical strain energy release rate in tension, GIC, and shear, GIIC). Therefore, it is crucial to understand how fracture appears under these circumstances, specifically how strain energy release rates in tension (GI) and shear (GII) compare to various crack propagation criteria or fracture envelopes. The main objective of this chapter is to verify, by cohesive zone models (CZM), which is the power parameter (\(\alpha\)) that best suits the energetic crack propagation criterion for CZM modelling, using single-lap joints (SLJ) and double-lap joints (DLJ) with aluminium adherends and bonded with three different adhesives. To achieve this, SLJ and DLJ numerical simulations are run, and the maximum load (Pm) is compared to experiments. The energy criterion obtained from the experimental study produced identical numerical findings for the Araldite® AV138 and Araldite® 2015, and the fracture envelopes were therefore validated. The Sikaforce® 7752 results were slightly offset due to CZM law shape issues.