Finite-distance singularities in the tearing of thin sheets
  We investigate the interaction between two cracks propagating in a thin sheet. Two different experimental geometries allow us to tear sheets by imposing an out-of-plane shear loading. We find that two tears converge along self-similar paths and annihilate each other. These finite-distance singularities display geometry-dependent similarity exponents, which we retrieve using scaling arguments based on a balance between the stretching and the bending of the sheet close to the tips of the cracks. 
E. Bayart, A. Boudaoud, and M. Adda-Bedia
cond-mat.mtrl-sci