PSAs were studied in the EU-funded project “MODIFY” aiming at building fundamental understanding of the role of material structure and properties in their performance. We modeled their mechanical test according to which a film is placed between two parallel disks. The disks are pulled away from each other and cavitating bubbles arise, expand and lead to a fibrilar structure and failure of the adhesive. We examine how this mechanism is affected by changes in the material rheological properties. The figure on the right is a snapshot of the simulations of an experiment reported by a French collaborator, where 163 bubbles were seen to cavitate. The dynamic and 3D simulation results are in very good agreement with experiments.
Top-left view: 163 Cavitating bubbles from the experiment by the French collaborating group. Bottom-left view: Cavitating bubbles from our simulations. Right-view: Detail of the cavitating bubbles
Cross sections of the mid plane of a cylindrical sample of PSA that contains an arbitrary number of deformable cavities, for different nominal elongational strains (ε) .