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Towards a microstructurally informed model for dynamic ductile failure

Justin Wilkerson (Johns Hopkins University), K.T. Ramesh (Johns Hopkins University)

Dynamic Behavior of Materials

Tue 9:00 - 10:30

Salomon 101

Dynamic ductile failure is a complex multiscale, multirate process. Upon nucleation, the voids undergo dynamic growth to coalescence, constrained by inertia and viscoplastic resistance to deformation. Void nucleation occurs at a finite number of pre-existing defects in the microstructure, e.g. second-phase particles, grain boundaries, and vacancy clusters. Both the spacing between void nucleation sites and the finite void growth rates govern the rate of tensile stress relaxation, and thus its rate-sensitive tensile strength. A predictive model is developed to understand the role of microstructure on the experimentally observed rate-sensitivity of dynamic tensile strength. In addition, we present a simple scaling law that captures the essential physics.