Scaling of crack propagation in rubber sheets

¹ Center for Nonlinear Dynamics and Department of Physics, The University of Texas at Austin Austin, TX 78712, USA
² Center for Mechanics of Solids, Structures and Materials and Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin - Austin, TX 78712, USA

^a marder@chaos.ph.utexas.edu

Received: 8 July 2011
Accepted: 12 September 2011

Abstract

We have conducted experiments and numerical simulations to investigate supersonic cracks. The experiments are performed at 85 ^°C to suppress strain-induced crystallites that complicate experiments at lower temperature. Calibration experiments were performed to obtain the parameters needed to compare with a theory including viscous dissipation. We find that both experiments and numerical simulations support supersonic cracks, and we discover a transition from subsonic to supersonic as we plot experimental crack speed curves vs. extension ratio for different sized samples. Both experiments and simulations show two different scaling regimes: the speed of subsonic cracks scales with the elastic energy density while the speed of supersonic cracks scales with the extension ratio. Crack openings have qualitatively different shapes in the two scaling regimes.