Anderson localisation and reentrant delocalisation of tensorial elastic waves in two-dimensional fractured media

Abstract

We study tensorial elastic wave transport in two-dimensional densely fractured media using numerical simulations and document transitions from propagation to diffusion and to localisation/delocalisation. For large fracture stiffness, waves are propagative at the scale of the system. For small stiffness, multiple scattering prevails, such that waves are diffusive in disconnected fracture networks, and localised in connected ones with a strong multifractality of the intensity field. A re-entrant delocalisation is found in well-connected fracture networks due to energy leakage via evanescent waves and cascades of mode conversion.