资源环境科技发展态势分析平台

The generation of acoustic emission (AE) in a material relates to the rapid energy release process, which delivers important information concerning the failure mechanism for stressed geologic materials. Here we report on ring-shear friction experiments to investigate the mechanical behavior and AEs for sheared granular materials with different particle sizes under constant normal stress and a range of shear rates. Results show that the mechanical behavior of shear resistance, sample compaction and slip displacement, and the release of acoustic energy can be affected by both shear rate and particle size. The main AEs are strongly correlated with the global mechanical failure, and the maximum absolute amplitude of AEs generally increases with increase of the magnitude of stress drops. By analyzing the event sequences, it is found that the onset of AEs precedes the beginning of stress drop, which provides more useful information on the failure mechanisms of geologic granular materials.