A New Approach to Asynchronous Variational Integrators for a Phase Field Model of Dynamic Fracture

Abstract

Phase field modeling of fracture has gained attention as a relatively simple and fundamental approach to predict crack propagation. However, the significant computational demands still pose challenges, particularly in dynamic simulations. To mitigate these challenges, we present a newly devised asynchronous variational integrator (AVI) for phase field modeling of dynamic fracture, implemented within the framework of the finite element library FEniCS. The AVI allows each spatial mesh element to progress independently with its own characteristic time step. In the new approach, displacement updates occur as usual at each time step, while the phase field is globally solved after the displacement update of the largest spatial mesh element rather than after each time step. Benchmark problems are investigated to assess the performance and reliability of the new method, revealing notable computational savings while effectively capturing intricate dynamic fracture behavior.