A volume deformation model for brittle rock based on fractional order calculus

Abstract

In compression and tension of brittle rock, the dilatancy phenomena of volume deformation were often observed. This paper presents experimental investigation of volume deformation properties of brittle rock samples in triaxial compression and uniaxial tension tests in different strain rate and different temperature in the laboratory. Based on the viscoelasticity mechanics principle, it is found that the combined effects of elastic and viscoelastic are the basic reason of causing the dilatancy in brittle rock. Moreover, In order to depict the dilatancy phenomena of volume deformation through a simple model presented and have a correct modelization of mechanical behaviors, a volume deformation model is proposed, in which the variation of volume deformation resulted from the combined effects is characterized through a fractional order calculus expression. Comparison between fitting results and experimental results reveals the presented model can describe the dilatancy phenomena of volume deformation of brittle rock.

DOI: http://dx.doi.org/10.5755/j01.mech.23.4.15119