Multiscale thermomechanical modeling of shock-driven dry friction in hydrodynamics

The purpose of the present work is to provide new insights in the understanding and computational modeling of shock-induced metal-on-metal dry friction. Based on a multiscale approach, we develop herein a 1D finite difference subgrid model. To adequately describe the physics of dynamic friction under shock-induced conditions, it accounts for frictional contact, elastoplastic yielding and work hardening, heating by friction and plastic work, thermal softening and melting, as well as dynamics effects. Temperature and dynamic elastoplasticity are predicted at a local scale through a nonlinear time implicit numerical solver. Two strategies have been considered for the coupling of the subgrid model to a standard thermoelastoplastic macroscopic model. The first one is velocity driven. Its implementation is rather straightforward, it leads to correct qualitative results but is restricted to sliding situations. To account for stick-slip cases, a second force driven downscaling strategy has been developed.