Failure analysis of adhesively bonded joints using a modulatory damage model

This article presents a novel approach to investigating the failure behavior of adhesively bonded joints (ABJs) in two different configurations of the single lap joint (SLJ) and double cantilever beam (DCB). The proposed approach utilizes a numerical-experimental procedure that incorporates a trapezoidal traction-separation cohesive zone model (CZM) with a modulator damage function. This damage function adjusts to account for parameters specific to ABJs. Additionally, the adhesive model includes graphene nanoplatelets, which are added in varying concentrations (ranging from 0 wt% to 0.5 wt%), to account for the mechanical properties of the adhesives in the new damage model. With a dual effect, the results indicate that the addition of graphene nanoplatelets enhances the elastic modulus and adhesive strength while simultaneously reducing the adhesive toughness (GT). Extensive analysis demonstrates that the updated damage model outperforms its predecessor in accurately predicting the behavior of ABJs. Furthermore, by deriving the energy release rate from GT, the presented model eliminates the need for determining the mode I energy release rate (GIC) through DCB tests when simulating ABJ failure.