Effect of strain-rate and moisture content on the mechanical properties of adhesively bonded joints

Abstract

Mechanical performance of polymer-based adhesive joints is susceptible to moisture absorption. In this respect, this study establishes a validated methodology for predicting the mechanical responses of adhesively bonded joints under strain rate-dependent and moisture conditions. For this purpose, adhesively bonded lap-joint specimens were tested under the opening (Mode I) and in-plane shear (Mode II) loadings at machine crosshead displacement rates up to 500 mm/min. The mechanics response of the adhesively bonded joint is predicted using the extended cohesive zone model to capture the strain rate- and absorbed moisture-dependent effects. Good correlation of the predicted and measured flexural responses are demonstrated for the independent case of the mixed-mode flexure (MMF) test configuration. The corresponding failure processes of the adhesively bonded joint are described in terms of the characteristic interface damage and stress evolution.