A modified phase-field model for cohesive interface failure in quasi-brittle solids.

We formulate a modified phase-field model for cohesive interface failure in quasi-brittle solids. Our model has two novel features: (i) a traction–separation-damage law for damage process; (ii) an energetic degradation function controlled by critical gap ratio. This modification offers an attractive approach to simulate the cohesive interface failure process. We also provide a robust numerical solution strategy to treat the spatio-temporal evolution of cohesive interface failure. Our model is validated by two benchmark problems including the constant strain patch test and mode-I delamination test. The numerical simulations are compared with some published data. We proceed to apply this model to study the complex failure mechanism of a peeling test on bi-material plates and crack impinging on interfaces in different scenarios, where the effects of critical gap ratios and interface inclination angles are discussed. [Display omitted] • A modified phase-field model is developed for cohesive interface failure analysis. • A traction–separation-damage law for interface failure process is proposed. • An energetic degradation function is developed by controlling critical gap ratio. • Staggered time integration strategy is proposed for stable solutions. [ABSTRACT FROM AUTHOR]