Large deformation effect in Mode I crack opening displacement of an Agar gel: A comparison of experiment and theory

In a recent work, Lefranc and Bouchaud (LB) showed that the Mode I crack opening displacement in a thin sheet of Agar gel deviates significantly from the square root profile predicted by linear elastic fracture mechanics. In this letter we re-examine this problem and show that the experimentally measured crack opening displacement is consistent with the prediction based on finite elastostatics and a hyperelastic strain hardening model.