HE Ming-ming, LI Ning, ZHU Cai-hui, et al. The volume deformation behavior of rock based on fractional calculus and its experimental study[J]. 2016, 37(11): 3137-3144.
DOI:
HE Ming-ming, LI Ning, ZHU Cai-hui, et al. The volume deformation behavior of rock based on fractional calculus and its experimental study[J]. 2016, 37(11): 3137-3144.DOI: 10.16285/j.rsm.2016.11.013.
The volume deformation behavior of rock based on fractional calculus and its experimental study
To provide better description for the volume deformation of rock
a lateral-axial strain fractional dashpot is presented on the basis of the Abel dashpot with a constant viscosity coefficient and a variable viscosity coefficient. A new model of volume-axial strain relationship is proposed based on fractional order calculus. The analytical solution for the model of volume-axial strain relationship is given theoretically. The new models have the advantages of solving volumetric strain of rock. Moreover
a multifunctional material testing setup is employed to measure volume-axial strain of various rock samples under the condition of triaxial compression
stress relaxation and uniaxial creep compression. The parameters of the volume-axial strain model are determined by regressing the experimental results of volume-axial strain of rock. In addition
a sensitivity study of the analytical solution of the volume-axial strain model is carried out
which shows the effects of confining pressure
fracture angle
fractional derivative order and model coefficient on volumetric strain of rock samples. It is found that the new models can describe not only the volumetric strain phenomenon of negative and positive dilatancy but also the stress relaxation and creep deformation characteristics in rock.