The Mechanical Properties of Granite under Ultrasonic Vibration

The new technique of using ultrasonic vibration to break hard rock is still in the experimental stage, but it has significant potential for improving the efficiency of hard rock crushing. We have analyzed the mechanical properties of granite under ultrasonic vibration and the characteristics of the damage produced. This was achieved by using an ultraloading device to apply continuous and discontinuous ultrasonic vibrations, respectively, to 32 mm diameter and 72 mm high granite samples. An ultradynamic data acceptor combined with strain gauges was used to monitor the strain of the granite in real time, and the elastic-plastic deformation behavior of the granite under ultrasonic vibration was observed. The results of this experiment indicate that the granite samples underwent elastic deformation, plastic deformation, and damage during this process. The samples first experienced compressive deformation with no obvious rupturing. As the vibration continued, the deformation finally became tensile, and significant fragmentation occurred. The mechanical properties of granite under ultrasonic vibration are analyzed in detail on the basis of these results, and the basis for selecting a vibration frequency is discussed.