Abstract: To study the dynamic constitutive model of rock in consideration of high-temperature damage,a novel modeling method is proposed.This model contains a fractured body and a damaged body connected in series with each other.Dynamic compression tests on granite were carried out with Split-Hopkinson pressure bar under temperature of 25-600 ℃.Results demonstrate that the dynamic peak stress of granite decreases with the climbing of temperature,while the elastic modulus firstly increases and then decreases.The pore characteristics of rock induced by high temperature can be reflected quantitatively by nuclear magnetic resonance test,and the T2 spectrum area displays an exponential growth with the rising of temperature.The adaptability of the proposed model is verified by the dynamic compression tests,and the correlation between theoretical and experimental data is over 0.98.The shape of compaction stage of stress-strain curve is controlled by parameters a and b of fracture body,of which parameter a has a larger influence.

Key words: fracture body, rock under high temperature, damage body, T2 spectrum area, dynamic constitutive model