Numerical Investigation of the Application of Cohesive Zone Models for Impact Strength Evaluation of Adhesive Bonded Joints

To be able to evaluate the performance and strength of an adhesive joint, numerical methodologies based on the Finite Element Method (FEM) are used. In real cases, adhesive joints are also subjected to dynamic loads, such as impact. This work aims to predict the behaviour and strength of double-lap composite adhesive joints under impact loads, under different overlap lengths (LO). For this purpose, numerical simulations by FEM and cohesive zone models (CZM) are considered. The adhesives used for this numerical study are the Araldite® AV138 and the Sikaforce® 7752. As adherend, the pre-preg Seal® Texipreg HS 160 RM was used. Initially, a study was carried out with single-lap joint (SLJ) experimental data, to validate the proposed technique for analysing impact-adhesive joints. Double-lap joint (DLJ) analysis was based on elastic peel (sy) and shear (txy) stresses, and strength prediction. Validation of the proposed numerical technique was successfully accomplished to model bonded joints under impact loads. Between the tested adhesives, stiff and strong adhesives work better under impact, leading to higher performance, although bigger LO than those tested in this work can benefit from less strong but more ductile adhesives.