ANALYSIS OF ENERGY DISSIPATION AND DAMAGE EVOLUTION OF SANDSTONE DURING TENSILE PROCESS

As a kind of complex inhomogeneous geological material,the mechanical response of rock behaviors distinct nonlinear and anisotropical characteristics.Direct tensile test of rock can be conducted by means of the advanced test system,accordingly the basic mechanical behavior of rock can be further studied in addition to the current numerous compression tests.It is observed during the cyclic tensile test of sandstone that the whole work of external applied load results in not only the increase of elastic deformation energy but also the irreversible damage because it is partly dissipated.Based on the analysis of such energy dissipation,a damage evolution equation of rock can be constructed;and the corresponding parameters can be determined through tests.Experimental study and theoretical research demonstrate that the damage evolution equation of rock based on the analysis of energy dissipation can well characterize the damage evolution process of rock.