multiscale experimental and numerical investigation of ROCksalt flow for underground STORage of HYdrogen – RockStorHy

Deep rock salt caverns may be used for massive storage of hydrogen. The long term mechanical evolution of the host rock must be assessed with strict respect of sealing at frequent operational cycling. This project is based on complementary multiscale approaches investigating experimentally and numerically the viscoplastic flow of rock salt. Our unique expertise will provide macroscopic flow laws, representative of both long term creep and cycled loading conditions. Triaxial testing coupled to X-Ray tomography and full mechanical field measurements will fallow to characterize ductile localization and to identify the active mechanisms, with especial focus on micro-damage and the influence of the deformation process on hydrogen permeation. Combining the experimental results and finite element numerical modelling will allow to derive a physically sound constitutive flow law for polycrystalline rock salt, which will be used for evaluation of cavern long term behavior.