Monitoring in situ stress-strain behaviour during plastic yielding in polymineralic rocks using neutron diffraction

摘要: Abstract Attempts to use rock deformation experiments examine the elastic and plastic behaviour of polymineralic rocks are hampered by fact that usually only whole sample properties can be monitored as opposed separate contribution each phase. To circumvent this difficulty, room-temperature, uniaxial compression were performed in a neutron beam-line on suite calcite + halite samples with different phase volume proportions. By collecting diffraction data during loading, strain hence stress was determined function load bulk strains 1–2%. In all cases, calcite behaved elastically while halite underwent yielding. During fully part deformation, composite within-phase stresses well-described both recent shear lag models analyses based Eshelby's solution for field around an ellipsoidal inclusion homogeneous medium. After onset yielding, situ stress/total curve may reconstructed using rule mixtures. At contents greater than 30%, response significantly weaker or stronger obtained at lesser contents. The results highlight potential such techniques offer developing explicitly experimental approach determining influence microstructural variables mechanical rocks.