This work introduces a computational fracture model for Ti64 alloy based on coupled Crystal Plasticity Phase Field model for fracture but also considers the atomistic mechanisms of plasticity at the crack tip. Atomistic simulations are conducted to identify the crack-tip mechanisms of plasticity and the continuum scale phase field model is augmented to account for this. Using the data generated using atomic scale Molecular Dynamic simulations, a functional form describing the evolution of dislocation density nucleating from the crack tip is obtained using Bayesian Inference and Genetic Programming based Symbolic Regression. The effect of nucleated dislocations in crack path and rate of crack propagation is evaluated. The additional plastic strain at the crack tip is also validated with results from Molecular Dynamics.
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