A line search algorithm for multiphysics problems with fracture deformation

We consider a poroelastic or thermoporoelastic problem in a fractured porous medium. The governing equations are strongly nonlinear and have reduced regularity at the fractures’ transition between the open and closed or sliding and sticking state, making them hard to solve. Herein, we propose a line search that efficiently computes the weights based on the fracture states. The algorithm ensures no fracture cells transition far into a new state within a single nonlinear iteration. We achieve reliable convergence in a few iterations across a range of challenging test cases.