Simulating Brittle Fracture With a Robust Hybrid Explicit–Implicit Solver for Staggered Phase‐Field Problems

Abstract In this work, the robustness of phase‐field fracture simulations is increased by introducing a new hybrid approach to take advantages of both explicit and implicit solvers. Switching to an explicit solver at critical load cases enables us to define a threshold on the maximum number of staggered iterations per load step. Having this threshold would be very useful in complicated FCM problems since we cannot wait for a full convergence of the implicit solver at critical load steps. With the new hybrid method, the problem is implicit as long as the implicit solver can converge within a specified threshold; otherwise, the failed load step will be solved robustly using an explicit approach. The method can resolve the highly nonlinear part of the global load–displacement curve. The superiority of the approach is shown in different benchmark examples.