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Center for Nonlinear Studies |
Recently, much attention has focused on gradient-based damage and phase-field models for fracture problems. Such approaches often suffer from a number of shortcomings when applied to dynamic fracture and fragmentation. These include, for example, the computational cost of a global reaction-diffusion auxiliary equation and challenges associated with introducing critical thresholds that trigger the onset of damage. We present a recent method for fracture and fragmentation that builds on the work of Lorentz and coworkers which established links between gradient-based damage models and cohesive models of failure. In particular, we incorporate a viscous regularization term that enables the use of a fully explicit treatment of the evolution equations. The approach naturally introduces a threshold for the onset of damage, and allows for a cohesive model to be recovered in the limit as the regularization length scale vanishes. We present results for a series of benchmark problems in large-scale dynamic fracture and fragmentation. We will also discuss progress on extended finite element methodologies to transition from regularized representations of failure surfaces to discontinuous representations.
Host: Mikhail Shashkov