On opening crack propagation in viscoelastic solids

TL;DR

This paper compares the Persson-Brener and cohesive-zone models for crack propagation in viscoelastic solids, highlighting their similarities and discussing finite-size effects and the implications of vanishing zero-frequency modulus.

Contribution

It demonstrates the equivalence of two prominent crack propagation theories in viscoelastic materials and discusses the effects of finite size and zero-frequency modulus.

Findings

Persson-Brener theory yields a similar fracture energy factor as the cohesive-zone model.

Finite-size effects influence crack propagation behavior.

Discussion on the applicability of crack theories to solids with zero zero-frequency modulus.

Abstract

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.