On numerical aspects of different updating schedules for tracking fracture path in strain localization modeling

A comparative study is performed that investigates numerical features of different schedules, end-of-step vs. within iterations, for updating fracture path by employing the local and global tracking strategies. Embedded strong discontinuities within an enhanced finite element framework are used to model propagating discontinuities and fracture behavior of quasi-brittle materials. It is shown that end-of-step updating, which is a standard, can cause inaccuracies in peak strength and fracture energy for large time steps. Updating within iterations rectifies the accuracy issues, but at the expense of an increased computational cost. Both schedules yield comparable performance as the step size is refined.