Implementation of the Thick Level-Set Method for Brittle Fragmentation

Andrew Stershic, Duke University

Dynamic fragmentation is characterized by intense forcing leading to widespread cracking and failure of a material. The prediction of failure strength, fragment size distribution and energy dissipation during dynamic fragmentation has been the subject of much study. The Thick Level-Set (TLS) model is a promising new method in the field of failure mechanics because of the efficiency and robustness of having a single level-set function that defines the extent and severity of regions of damage within the domain. This allows for straightforward implementation and evaluation of crack nucleation and merging. A non-local damage model, the TLS approach introduces a length scale parameter that limits the damage gradient, preventing the strain localization phenomenon that causes mesh dependence. This method is applied to dynamic fragmentation of a brittle material to compare results against analytical predictions and existing numerical models. The results of our analysis show that the TLS model can successfully replicate the rate-dependent fragment size and energy dissipation predictions of the cohesive zone model.

Abstract Author(s): Andrew Stershic, John Dolbow, Nicolas Mo√ęs