EXPERIMENTAL INVESTIGATION ON FAILURE OF ROCK BY DIGITAL SPECKLE CORRELATION METHODS

The experiments of the deformation and failure of rock under the condition of uniaxial compression were carried out by using the white digital speckle correlation methods.According to the experimental data collected in different ways,the experiments were divided into two groups.A group of experiment investigated the deformation evolution process of rock loaded,the specimen surface speckles images were recorded by CCD camera,According to the calculation results,the rock deformation evolution was studied.The other group of experiment investigated the deformation evolution process of the transient of rock damage;the specimen surface speckles images were recorded by adopting high speed cameras.By adopting the different times speckle images as reference frame,the plastic hardening to peak stage deformation evolution characteristics and the peak to destroy phase analysis of deformation evolution characteristics were carried out.At the same time,some quantitative parameters were obtained in the experiments,such as the value of deformation,the ratio of maximum and minimum values of the deformation in the deformation localization band,the ratio of deformation values inside and outside the deformation localization band,and the average speed of crack propagation.