In the rock cutting process, conical pick wear is often encountered. In order to restrain this condition, a saw blades and conical pick combined cutting method was put forward. Saw blades were employed to slit the rock for increasing the free surface, and then the conical pick was used to break the rock. To research the cutting performance of the new cutting method, the corresponding experimental device and a three‐dimensional finite element model are established. In order to obtain crack propagation and fragment separation and to study the fracture process of the rock plate, a damage constative model and failure mechanism were combined in the numerical model. The mechanical tests were carried out to achieve the mechanical parameters of the rock. To investigate different parameters affecting rock plate cutting performance, experiments with different compressive strengths, physical parameters, and cutting depths were carried out. Moreover, the confining pressures affecting the cutting performance were adopted to simulate deep mining conditions. The experimental results demonstrated that the peak cutting force shows the exponential positive correlation with compressive strength, thickness of the rock plate, and cutting depth of the conical pick, and exhibits the exponential positive correlation with rock plate height and width. Besides, the numerical simulation results show that peak cutting force and confining pressure have a binomial relationship.
Gravel and sediment frequently build up in holes during the anchor cable installation process, which makes it harder to install the anchor cable and causes reinforcement to fail, which can lead to accidents. In this paper, a bit anchor setup approach is proposed to set up a drill bit at the front of the anchor cable to aid the anchor cable drilling. The feasibility of this approach is established with the aid of DEM-MBD joint simulation and proves the correctness of the simulation model. The major elements affecting drilling effectivity have been studied by the use of ‘check + simulation’. The effects exhibit that the axial velocity and working aperture are negatively correlated with the drilling resistance of the anchor cable; the feed price is positively related to the anchor cable drilling resistance; with the increase in anchor cable pitch, the drilling resistance of the anchor cable changes into a hump shape. When the bit is 0.2 m from the backside of the hole, the particle pace vector at the decrease stop of the bit gives a conical distribution. This paper is of fantastic magnitude in relation to the environment-friendly setup of anchor cables and protection against disasters.
1 August 2024 in Eksploatacja i Niezawodność – Maintenance and Reliability
When a roadheader breaks hard rock in a roadway, the excessive cutting load causes the conical pick to experience abnormal wear, which impacts equipment stability. To improve the reliability of hard rock cutting equipment, the dynamic characteristics of prefabricated grooved rocks during cutting were investigated using a single pick cutting experimental bench in rock crushing experiments, and a conical pick cutting rock breaking finite element model was established. The rock stress state under different cutting depths and spacing conditions was analyzed, and the cutting force and the trend of the change in the specific energy consumption were elucidated. The results show that prefabricated grooves can effectively reduce the cutting load and specific energy consumption, the cutting depth and conical pick–groove spacing are the key factors affecting the cutting characteristics, and a reasonable choice of spacing and depth can help reduce the wear of conical picks and improve the working reliability of roadheaders.