title: Path (un)predictability of two interacting cracks in polycarbonate sheets using Digital Image Correlation.
abstract: Crack propagation is tracked here with Digital Image Correlation analysis in the test case of two cracks propagating in opposite directions in polycarbonate, a material with high ductility and a large Fracture Process Zone (FPZ). Depending on the initial distances between the two crack tips, one may observe different complex crack paths with in particular a regime where the two cracks repel each other prior to being attracted. We show by strain field analysis how this can be understood according to the principle of local symmetry: the propagation is to the direction where the local shear - mode KII in fracture mechanics language - is zero. Thus the interactions exhibited by the cracks arise from symmetry, from the initial geometry, and from the material properties which induce the FPZ. This complexity makes any long-range prediction of the path(s) impossible.
authors: Aalto University, Department of Applied Physics, PO Box 14100, 00076 Aalto, Finland.
authors: J
authors: J
authors: Koivisto
authors: Laboratoire de Physique de l'Ecole Normale Supérieure de Lyon, UMR CNRS 5672, Université de Lyon, 69634 Lyon Cedex 07, France.|Institut Lumière Matière, UMR5306 Université de Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne, France.|Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors: M-J
authors: MJ
authors: Dalbe
authors: Aalto University, Department of Applied Physics, PO Box 14100, 00076 Aalto, Finland.
authors: M J
authors: MJ
authors: Alava
authors: Laboratoire de Physique de l'Ecole Normale Supérieure de Lyon, UMR CNRS 5672, Université de Lyon, 69634 Lyon Cedex 07, France.
authors: S
authors: S
authors: Santucci