Study on dynamic mechanical properties of granite at real time high temperature

ABSTRACT: Vibration impact drilling technology is an effective means to break up hot dry rock, the rock is affected by both temperature and strain rate under the impact condition, and the mechanical properties of rock cannot be accurately characterized by conventional static mechanical tests. In order to study the dynamic mechanical properties of granite under real-time high temperature and different strain rates, an improved split Hopkinson pressure bar (SHPB) experimental device was developed, the dynamic mechanics test of high temperature granite was carried out. The results show that with the increase of temperature, the fracture frequency in granite first increases and subsequently declines. As the number of impacts increases, the peak stress demonstrates a declining trend, whereas the failure strain displays an ascending trend, signifying a shift from brittle to plastic failure modes. The research in this paper provides theoretical support for granite crushing under high temperature and confining pressure, which is of great significance to field practice.