Orateur : Marie-Julie Dalbe
ENS Lyon
Titre : "Stick-slip during the peeling of adhesive tape"
Date et lieu : le Vendredi 28 Novembre 2014 à 11h00, IRPHE
Résumé : We present different experimental set-ups allowing us to observe directly the stick-slip dynamics during peeling.
The experiments are conducted at an imposed velocity and different geometries : the adhesive is peeled directly from its roll, or from a flat substrate at a fixed angle. We highlight the existence of strong dynamical effects, which cannot be understood with the existing theoretical models. We also show the crucial effect of the peeling angle on the instability, which is strongly reduced at large angles. Besides, a new theoretical approach, taking into account the ribbon inertia, can allow us to understand partially the experimental observations.
Finally, we show that the stick-slip instability is multi-scale : a secondary instability can occur at spatial and temporal scales smaller than the usually observed stick-slip. While the main instability is due to variations of the stretching elastic energy, this secondary instability is driven by the release of the bending energy stored in the ribbon.