Analysis Of Energy Dissipation Characteristics Of Rock Cutting Under Mechanical Impact Load

With the development of industrial and social economic activities, the workload ofrock crushing in which people engaged is increasing. The exploration and development ofsolid, gas, liquid ore deposit and the construction of many underground engineering, etc.,generally involve rock fragmentation. At present, the rock fragmentation is involved inmining engineering, tunnel engineering, slope engineering, military engineering,earthquake engineering and many other important disciplines and engineering fields. Inthe construction technology of drilling, blasting, cutting and rolling, the proportionof effective energy used for rock fragmentation is very low compared with the total inputenergy. Therefore, in the process of rock breaking, energy dissipation is widely concerned.It is not only the key to optimize rock fragmentation efficiency and improve theproduction capacity, but also the theoretical basis to control rock fragment size.Based on the sandstone cutting experiment, experimental data and related results byusing the linear rock cutting machine at the school of mining engineering, University ofNew South Wales (UNSW), the experimental data were collated and analyzed, thecharacteristics of mass distribution and rock fragment size were studied, and therelationship between cutting force and specific energy of rock breaking were statisticallyanalyzed. The computational model was built by using particle flow code (PFC), and theseparameters such as cutting speed, cutting depth, rock temperature, rock strengthuniformity, rock porosity, rock confining pressure were artificially changed. In this article,the characteristics of specific energy of rock breaking were analyzed by using the built-inENERGY function to get an optimal cutting depth and provide a reference basis for theengineering practice. The characteristics of acoustic emission (AE) were analyzed byusing the built-in CRACK function to study rock brittle failure mechanism and reveals thedevelopment process of rock breaking. The characteristics of energy utilization wereanalyzed with an self-defined energy utilization coefficient to evaluate the difficulty ofrock breaking.By using the PFC2D procedure to simulate the cutting process, these parameters including cutting speed, cutting depth, rock temperature, rock strength uniformity, rockporosity, rock confining pressure were adjusted to analyze their influence on energyconsumption of rock cutting, acoustic emission characteristics and energy utilization. Thestudy in this article which provides theoretical basis and technical support for the designof mechanical rock crushing, optimizes rock fragmentation efficiency and improves theengineering production capacity undoubtedly has important theoretical significance andpractical engineering value.