Abstract:
In order to study the mechanic responding mechanism of rock materials under cyclic loading and unloading, uniaxial cyclic loading and unloading tests were carried out to investigate the non-uniform deformation evolution processes of granite specimens. The deformation images of specimens during the tests were collected by CCD camera and based on the digital speckle correlation method,the non-uniform deformation,the evolution laws of the characteris- tic parameters of the localization during cyclic loading and unloading were analyzed. The research results show that: With the increase of cycle numbers,the non-uniform deformation is more and more obvious. The statistical index Sw of non-uniform deformation increases with the increase of loading stress,and increases with the increase of cycle num- bers. After the localization of a specimen appears,the extrusion displacement and the influence width of the localization band all increase with the increase of stress and cycle numbers in the subsequent cycles.