| Popis: |
Analysis of rock acoustic emission characteristics in complete stress-strain process under uniaxial compression shows that the evolution process of rock deformation and damage can be divided into five stages—compaction, linear elastic deformation, accelerate inelastic deformation, damage and development, plastic flow. Acoustic emission characteristics of rock can well reflect its compressive deformation and damage evolution process. Acoustic emission time series of typical plastic coal is comparatively dispersed and presents group shock type. The acoustic emission frequency events and their energy of coal are bigger around the damage point, but the maximum amplitude and the secondary maximum amplitude have not much difference. The acoustic emission events and their energy of very uniform and dense fragile limestone are mainly concentrated in a very short period of time before its damage and the acoustic emission time series manifests as isolated shock type. For sandstone whose homogeneous degree lies between typical plastic coal and very uniform and dense fragile limestone, its acoustic emission time series manifest as main shock type. |
