Impact loading analysis of double-lap composite bonded joints

Abstract

Currently, static modelling of adhesive joints is mostly understood, oppositely to dynamic problems, including impact. However, the literature is still scarce on the impact analysis of bonded joints, with preponderance to cohesive zone models (CZM). This work aims to predict the behaviour and strength of composite adhesively-bonded double-lap joints (DLJ) under impact loads, under different overlap lengths (LO). For this purpose, numerical simulations by the finite element method (FEM) and CZM are considered. The adhesives used for this numerical study are the Araldite® AV138 and the Sikaforce® 7752. Initially, a study was carried out with single-lap joint (SLJ) experimental data, acquired from a previous work, to validate the proposed technique to analyse impact-adhesive joints. DLJ analysis was based on elastic peel (σy) and shear (τxy) stresses, load-displacement (P-δ) curve analysis, and strength prediction. A CZM parameter-influence analysis on the DLJ strength predictions was also carried out. Validation of the proposed numerical technique was successfully accomplished to model bonded joints under impact loads. On the other hand, clear design guidelines were provided for these joints under impact.