Fig. 2: XFEM models and simulation results.
From: Experimentally measuring weak fracture toughness anisotropy in graphene
a Sample geometry, loading conditions, local energy release rate (G(θ)), and the anisotropy in fracture toughness (\({G}_{{{{{{{{\rm{c}}}}}}}}}^{-1}(\theta )\), plotted for two values across R = 0.87) at the crack tip. The stress intensity factors KI, KII and \({\tilde{K}}_{{{{{{{{\rm{I}}}}}}}}},{\tilde{K}}_{{{{{{{{\rm{II}}}}}}}}}\) (see Methods for details). b-e Crack-path predictions and standard deviations measured from the experimental data for Sample 1 (b, c) and Sample 2 (d, e), respectively. The results are obtained by varying R = GA/GZ in the range of [0.74, 1.07].
