On Opening Crack Propagation in Viscoelastic Solids

We show that the Persson-Brener theory of crack propagation in viscoelastic solids gives a viscoelastic fracture energy factor G/G 0 = 1 + f which is nearly the same as the viscoelastic factor obtained using the cohesive-zone model. We also discuss finite-size effects and comment on the use of crack propagation theories for “solids” with a viscoelastic modulus that vanishes at zero frequency.