Influence of Adhesion on the Mechanical Response of Granular Composites

Abstract

The adhesion energy between the polymer binder and granular crystals strongly influence the mechanical properties of granular composites under different loading conditions. Thus, the accurate measurement of interfacial adhesion is necessary for the accurate description of the mechanical behavior and failure of granular composites. In the current work, an experimental setup capable of performing a peel test at different displacement rates (10 nm/s–1 mm/s) and peel angles (45°–135°) has been developed to experimentally quantify interfacial adhesion between soft elastomer (binder) and hard substrates (crystals). Since the elastomeric binder in many granular composites materials can be viscoelastic in nature, a time-dependent mathematical framework was adopted to calculate interfacial adhesion for these viscoelastic peel test experiments. Thus, the framework allows for the quantification of interfacial adhesion between different combinations of viscoelastic binders and crystals as a function of peel rate and angle. High-resolution optical microscope and digital image correlation was employed to capture the displacement and strain fields of both linear elastic and viscoelastic material under different conditions.