The importance of linear search for the bound-constrained solver for phase- field modeling of fracture in quasi-brittle materials with FEM

Resumo

The propagation and emergence of cracks are widely explored in fracture mechanics. A study that
has increased with the advancement of computer technology is the phase-field for crack modeling. This model
approaches the crack as continuous and diffuse, placing a damage variable in the problem and a variable with the
crack band size. There are different ways to control crack irreversibility, such as the bound-constrained solver
and the historical solver. The bound-constrained solver allows you to choose any crack geometry function and
energy degradation while the historical solver needs to be a specific crack geometry function. In this article, the
importance of linear search for bound-constrained solver results will be discussed through numerical simulations,
showing that the line search is necessary to avoid numerical instabilities as well as a correct load peak. Numerical
simulations were processed in INSANE software (INteractive Structural ANalysis Environment). This work uses a
bound-constrained solver from the PETSc library, connected to INSANE through a JNI.