Cohesive zone micromechanical model for compressive and tensile failure of polycrystalline ice

In this work, a cohesive zone model is applied to model fracture behavior of polycrystalline cylindrical samples under uniaxial loading conditions. The model is based on the implicit finite element method that is combined with Park-Paulino-Roesler formulation for cohesive potential. We implement an adaptive time stepping scheme that takes into account the rate of damage and failure of cohesive zones. Material properties and model parameters have been calibrated using available experimental data for laboratory-made freshwater ice samples. Simulations are performed for samples with different grain sizes, and the resulting stress-strain and damage accumulation curves are recorded. Investigation of the dependency between the grain size and fracture strength shows a strengthening effect that is consistent with experimental results. Fracture patterns observed in simulated failure events are also consistent with observations from experiments.