Stick-slip during the peeling of an adhesive
Collaborators : Stéphane Santucci, Loïc Vanel, Pierre-Philippe Cortet, Matteo Ciccotti , Baudouin Saintyves, Costantino Creton, Richard Villey, Jean-Pierre Hulin.
When you peel off a roller adhesive tape, you can hear a characteristic screeching sound. This is due to a physical instability called stick-slip. Even if you pull at a given velocity at the end of the tape, the fracture line velocity oscillates between high and low values. This instability causes different challenge in the industry : for example, at the scale of an industry, the noise can be unbearable, or the tape can be damaged and lose its adhesive properties. With different experiments, we are measuring the main characteristics of stick-slip (velocity, duration, amplitude) and their evolution with the parameters (length of the peeled tape, imposed velocity, peeling angle).
Interaction of two cracks in polycarbonate sheets
Collaborators : Stéphane Santucci, Loïc Vanel, Osvanny Ramos, Mikko Alava, Juha Koivisto
When submitted to uniaxial stress, a crack in a polycarbonate sheet grows in a very specific way : a macroscopic flame-shaped process zone appears at the tip of the crack. We study experimentally how two cracks interact with each other in such a material.
