Investigation of acoustic emission accompanying stick-slip movement of rock samples at different stiffnesses of spring–block system

Understanding of friction process, especially, transition from stable to stick-slip motion, is very important in various fields from mechanical engineering to seismology. It seems that analysis of acoustic emission (AE) accompanying the friction process can be a sensitive tool for revealing fine details of the friction process. In the present work, acoustic emission accompanying the stick-slip movement of basalt samples has been investigated in laboratory slider-spring device. Exactly, the influence of spring stiffness on the statistical and dynamical characteristics of stick-slip generated AE has been studied. Different time series compiled from recorded AE wave trains have been analyzed using statistical and dynamical data analysis methods. We found that statistical and dynamical changes in acoustic emission of stick-slip movement depend on the stiffness of spring in spring–block system. The obtained results show that dynamics of stick-slip process undergoes both qualitative and quantitative changes at transition from stick-slip to stable sliding friction caused by increased stiffness of frictional system. Extent of regularity in stick-slip process, assessed by analysis of AE temporal distribution characteristics, increases at stiffer springs.