scholarly journals Coal Rock Breaking Simulation and Cutting Performance Analysis of Disc Cutters

2021 ◽  
Vol 28 (5) ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 639-646
Author(s):  
Zhenggang Guo ◽  
Juan Wang ◽  
Shuai Lv ◽  
Deyue Yu ◽  
Xu Zhang

In unstable coal rock formations, the rescue channels should be constructed through safe and efficient tunneling. The rock breaking performance of the tunneling equipment directly hinges on the cutter-head layout. Focusing on the conditions of unstable coal rock formation, this paper adopts the extended Drucker-Prager (D-P) plastic model to define the properties of bedrock materials of the coal rock with low mechanical strength and poor homogeneity. Then, a finite-element model was established on ABAQUS for the coal rock cut by two disc cutters, and used to simulate the breaking of the coal rock and the peeling of slags from the bedrock. On this basis, the authors analyzed the influence of cutter spacing (30, 35, 40, and 45mm) over cutting force, rock breaking amount, and specific energy under two cutting methods: simultaneous cutting and sequential cutting. Finally, a cutter deployment strategy was designed for safe and efficient tunneling in unstable coal rock formations. The results show that: Under simultaneous cutting, as the cutter spacing increased from 30 to 35mm, the rock breaking amount increased, while the specific energy declined; as the cutter spacing further rose from 35 to 45mm, the rock breaking amount dropped, while the specific energy increased. Under the coal rock conditions in our research, the optimal cutter deployment strategy is: simultaneous cutting with cutter spacing of 35mm. The research results provide theoretical support for the cutter-head design of rescue equipment for collapsed coalmines.


2019 ◽  
Vol 6 (5) ◽  
pp. 190116 ◽  
Author(s):  
Si-fei Liu ◽  
Shuai-feng Lu ◽  
Zhi-jun Wan ◽  
Jing-yi Cheng

Rock damage is one of the key factors in the design and model choice of mining machinery. In this paper, the influence of rock damage on rock fragmentation and cutting performance was studied using PFC 2D . In PFC 2D software, it is feasible to get rock models with different damage factors by reducing the effective modulus, tensile and shear strength of bond by using the proportional factors. A linear relationship was obtained between the proportion factor and damage factor. Furthermore, numerical simulations of rock cutting with different damage factors were carried out. The results show that with the increase of damage factor, the rock cutting failure mode changes from tensile failure to brittle failure, accompanied by the propagation of macro cracks, the formation of large debris and a notable decrease in the peak cutting force. The mean cutting force is negatively correlated with the damage factor. Besides this, the instability of cutting force was evaluated by the fluctuation index and the pulse number of unit displacement. It was found that the cutting force was quite stable when the damage factor was 0.3, which improves the reliability of cutting machines. Finally, the cutting energy consumption of rock cutting with different damage factors was analysed. The results reveal that an increase of damage factor can raise the rock cutting efficiency. The aforementioned findings play a significant role in the development of assisted rock-breaking technologies and the design of cutting head layout of mining machinery.


2014 ◽  
Vol 615 ◽  
pp. 22-26
Author(s):  
Xiang Heng Zhu ◽  
Yi Min Xia ◽  
Tao Ouyang ◽  
Kai Yang

Cutterheads and disc cutters are the key components of Tunnel Boring Machine (TBM) used to fulfill the rock-breaking task. In order to study the variation and distribution law of cutting forces induced by disc cutters on TBM cutterhead, a finite element model of rock-breaking process is established based on the extended Drucker-Prager yield criterion for rock and then the excavating process of cutterhead is simulated. The simulation results show that: in the rock fragmentation process, the rock-breaking forces are step changing; with the increase of installation radius, the vertical forces of inner and face cutters increase, while the lateral forces decrease; with the increase of installation angle, the vertical forces of edge disc cutters decrease, while the lateral forces increase; the mean total thrust and torque of cutterhead are 5418.2 kN and 1624.4 kN·m respectively, the simulation results are verified by engineering data.


2022 ◽  
Author(s):  
Xin Jin ◽  
Guochao Zhao ◽  
Lijuan Zhao ◽  
Guocong Lin

Abstract The cutting head is the core working mechanism of the roadheader for coal-rock materials cutting. The efficient and high performance design of cutting head is the key to improve the road head digging and mining technology. In this paper, based on cutting head design theory and virtual prototype technology, we propose a computer-aided structure design and performance optimization method for cutting head. We compile the calculation code and realize the reading and storing of relevant data through Excel. In particular, to obtain more realistic cutting performance data of the cutting head, we construct a coupling model of cutting head cutting rock wall based on virtual prototype technology, and then establish a database matching structural parameters, working parameters, coal-rock properties and cutting performance through extensive simulations. Based on the method, we complete the design of EBZ220 roadheader cutting head. We show that our method can realize the fast and efficient design of cutting head, and the designed cutting head has good working performance.


2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Qinglong Zhang ◽  
Yanwen Zhu ◽  
Canxun Du ◽  
Sanlin Du ◽  
Kun Shao ◽  
...  

Rock-breaking efficiency of full-face rock tunnel boring machine (TBM) is closely related to the performance of the disc cutter and the characteristics of the rock mass. In the point of view of mesomechanics, the particle flow code (PFC) is used to establish a numerical model of the rock mass and the disc cutter, and the process of TBM disc cutter intrusion into the rock mass is analyzed. The dynamic response mechanism and crack evolution process of the rock mass under the action of the disc cutter are studied on the basis of micromechanics, and the relationship between the rock mass crack, penetration, and cutting force during the intrusion of the disc cutter is revealed. The sensitivity analysis is carried out on the confining pressure conditions and the influence parameters of the disc cutter spacing. The results show that the rock breaking by disc cutter undergoes the transformation characteristics of compaction, shearing, and tension failure modes, and the failure process of the rock mass is the joint action of tension and shear. In the whole process of rock breaking, the disc cutter has the phenomenon of repeated loading-unloading alternation and leaping rock breaking; after the penetration of the disc cutter reached 9.0 mm, penetration creaks begin to appear on the surface of the rock mass; the penetration was obviously reduced with the increase of confining pressure, and it is mainly the penetration cracks on the surface; after the disc cutter spacing reaches 100.0 mm, there is no penetration crack between the two disc cutters. The research conclusion can provide a reference for the disc cutter optimization design.


2018 ◽  
pp. 65-68
Author(s):  
A. B. Zhabin ◽  
◽  
A. V. Polyakov ◽  
E. A. Averin ◽  
◽  
...  

2013 ◽  
Vol 690-693 ◽  
pp. 2484-2489 ◽  
Author(s):  
Peng Zhou ◽  
Chao Wang ◽  
Wei Xian Gao ◽  
Yu Hou Wu

Rock tunnel boring machine is one of the main machineries and equipments for underground engineering, and the failure of tool systems is its main failure form. Rock hob test-bed is the only testing equipment for tool failure and wear. In this paper, the breaking rock by the double disc cutter is simulated and four kinds of rocks are selected to test the influece of rock characteristics and spacing between two disc cutters on the rock breaking by the double disc cutter test-bed. The results show that there is different optimal spacing between two disc cutters for different rock; the optimal spacing is inversely proportional to the hardness of the rocks; the maximum stress appears the boundary between the disc cutter and rock.


2021 ◽  
Vol 861 (6) ◽  
pp. 062085
Author(s):  
Xin Jin ◽  
Shunhui Yang ◽  
Zhiqiang Hu ◽  
Xianzhi Song ◽  
Hongbao Zhang ◽  
...  

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