title: Repulsion and Attraction between a Pair of Cracks in a Plastic Sheet.
abstract: We study the interaction of two collinear cracks in polymer sheets slowly growing towards each other, when submitted to uniaxial stress at a constant loading velocity. Depending on the sample's geometry-specifically, the initial distances d between the two cracks' axes and L between the cracks' tips-we observe different crack paths with, in particular, a regime where the cracks repel each other prior to being attracted. We show that the angle θ characterizing the amplitude of the repulsion-and specifically its evolution with d-depends strongly on the microscopic behavior of the material. Our results highlight the crucial role of the fracture process zone. At interaction distances larger than the process zone size, crack repulsion is controlled by the microscopic shape of the process zone tip, while at shorter distances, the overall plastic process zone screens the repulsion interaction.
authors.affiliation: Laboratoire de Physique de l'Ecole Normale Supérieure de Lyon, UMR CNRS 5672, Université de Lyon, 69364 Lyon Cedex 07, France.|Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne, France.
authors.forename: Marie-Julie
authors.initials: MJ
authors.lastname: Dalbe
authors.affiliation: COMP Center of Excellence, Department of Applied Physics, Aalto University, 00076 Aalto, Espoo, Finland.
authors.forename: Juha
authors.initials: J
authors.lastname: Koivisto
authors.affiliation: Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne, France.
authors.forename: Loïc
authors.initials: L
authors.lastname: Vanel
authors.affiliation: COMP Center of Excellence, Department of Applied Physics, Aalto University, 00076 Aalto, Espoo, Finland.
authors.forename: Amandine
authors.initials: A
authors.lastname: Miksic
authors.affiliation: Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne, France.
authors.forename: Osvanny
authors.initials: O
authors.lastname: Ramos
authors.affiliation: COMP Center of Excellence, Department of Applied Physics, Aalto University, 00076 Aalto, Espoo, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Alava
authors.affiliation: Laboratoire de Physique de l'Ecole Normale Supérieure de Lyon, UMR CNRS 5672, Université de Lyon, 69364 Lyon Cedex 07, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Santucci