Fatigue and Acoustic Emission Characteristics of Granite under Different Cyclic Loading Paths.

A large number of experiments were performed to systematically investigate the evolution of the acoustic emission characteristics, dynamic elastic modulus, and axial residual strain of rock under different cyclic loading paths. These results provide experimental support for the damage accumulation and fatigue/failure characteristics of rock structures, and for the construction of a new nonlinear fatigue cumulative damage model suitable for rock materials. More active acoustic emissions are associated with greater acoustic emission intensity, which reflects the association between the dynamic elastic modulus and greater damage. Under increasing cyclic loading, the axial residual strain increases stepwise with increasing load level, following a nonlinear function. Under decreasing cyclic loading, the axial residual strain decreased stepwise and nonlinearly with decreasing load level. [ABSTRACT FROM AUTHOR]