Numerical modeling of adiabatic heat generation during rock fracture under dynamic loading

This paper considers adiabatic heat generation during rock fracture under dynamic loading. To this end, a thermo-viscoplastic constitutive model for rock based on Mohr-Coulomb and Rankine criteria augmented with the adiabatic heat equation is developed. Young's modulus and the compressive and tensile strengths are taken as the temperature-dependent parameters. A numerical solution algorithm based on the Newton-Raphson iteration and the cutting plane algorithm at the material point level is presented. Furthermore, there is a description of an explicit staggered scheme for solving the heat conduction at the specimen level in rock material. Then, the model is applied in 2D and 3D numerical simulations of compression and tension tests on a rock-like material with compressive and tensile strengths of 120 and 10 MPa, respectively. The simulations predict that the temperature rise because of adiabatic heat generation during rock fracture is in the order of a few degrees centigrade, even at a strain rate of 100 s(-1). In conclusion, the effect of including heat conduction is shown to be insignificant because of the short duration of dynamic loading processes.