基于离散元法的机械破岩多参数耦合与预切槽协同效应研究

Multi-parameter coupling and pre-cut groove synergistic effects in mechanical rock breaking based on the discrete element method

摘要

针对镐型截齿破岩过程中切削深度、攻击角与预切槽的协同作用机制不明问题，采用离散元软件MatDEM构建二维破岩模型，通过全因子设计系统分析线性切削阶段的刀具力动态特性、裂纹扩展模式及预切槽影响。研究发现：浅切深下破岩以“张拉主导”，攻击角40°～55°时平均切削力稳定在80～90 N，对应张拉裂纹数量550～600条；深切深转向“剪切主导”，平均切削力随攻击角增至60°时达150 N，剪切裂纹维持850～950条。预切槽通过诱导力链重分布，促进表层剥落，深切深时强化“剪切破碎区”穿透性破坏。基于配位数云图揭示的细观接触演化，建立“切深-攻击角-预切槽”协同判据：针对砂岩（中硬岩），浅切深适用于40°～50°攻击角加以预切槽控制损伤，深切深推荐55°～60°攻击角加以预切槽提升效率，为截齿破岩参数优化提供跨尺度理论支撑。

Abstract

The synergistic mechanism among cutting depth, attack angle and pre-cut groove in conical-pick rock fragmentation remains unclear. Therefore, a two-dimensional linear-cutting model was constructed in the open-source discrete-element code MatDEM and tested through a full-factorial experimental design. Dynamic pick forces, crack-evolution patterns and the mediating effect of a pre-cut groove were quantitatively captured. Results show that at shallow depths (≤12 mm) fragmentation is tensile-dominated, with the mean cutting force stabilizing at 80 N-90 N for attack angles of 40°-55° and 550-600 tensile cracks generated; at the deep depth (15 mm) the mechanism switches to shear-dominated, the mean force rising to 150 N at 60° while 850-950 shear cracks persist. The pre-cut groove redistributes force chains to promote surface spalling, and under deep cutting, intensifies the penetration of the shear-crushing zone. Coordination maps extracted from temporal coordination-number fields yield a cross-scale criterion: for medium-hard sandstone, shallow cutting benefits from 40°-50° attack angles combined with a pre-cut groove to control damage, whereas deep cutting favors 55°-60° angles coupled with a pre-cut groove to enhance efficiency, thus providing a mechanistic basis for parameter optimization of conical-pick rock fragmentation.

关键词

镐型截齿 / 切削深度 / 攻击角 / 预切槽

Key words

conical pick / cutting depth / attack angle / pre-cut groove

参考文献

[1] 刘送永, 李洪盛, 江红祥, 等. 矿山煤岩破碎方法研究进展及展望[J]. 煤炭学报, 2023， 48（2）: 1047-1069.

[2] LIU Songyong, LI Hongsheng, JIANG Hongxiang, et al. Research progress and prospect of coal-rock breaking methods in mines[J]. Journal of China Coal Society, 2023, 48(2): 1047-1069(in Chinese).

[3] XIE L X, LU W B, ZHANG Q B, et al. Damage evolution mechanisms of rock in deep tunnels induced by cut blasting[J]. Tunnelling and Underground Space Technology, 2016, 58: 257-270.

[4] YANG J H, LU W B, JIANG Q H, et al. Frequency comparison of blast-induced vibration per delay for the full-face millisecond delay blasting in underground opening excavation[J]. Tunnelling and Underground Space Technology, 2016, 51: 189-201.

[5] HAMZABAN M T, ROSTAMI J, DAHL F, et al. Wear of cutting tools in hard rock excavation process: a critical review of rock abrasiveness testing methods[J]. Rock Mechanics and Rock Engineering, 2023, 56(3): 1843-1882.

[6] YANG L, YU T B, LI M, et al. Microstructure and wear resistance of in-situ synthesized Ti(C,N) ceramic reinforced Fe-based coating by laser cladding[J]. Ceramics International, 2018, 44(18): 22538-22548.

[7] 张佳琦, 苏翠侠, 刘浩飞, 等. 一种高效的刀盘掘进过程数值模拟算法[J]. 应用力学学报, 2024， 41（6）: 1306-1316.

[8] ZHANG Jiaqi, SU Cuixia, LIU Haofei, et al. An efficient numerical simulation algorithm of cutterhead driving process[J]. Chinese Journal of Applied Mechanics, 2024, 41(6): 1306-1316(in Chinese).

[9] EVANS I. Line spacing of picks for effective cutting[J]. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1972, 9(3): 355-361.

[10] 刘春生, 任春平. 基于离散正则化的实验载荷谱重构与推演算法[J]. 应用力学学报, 2014（4）: 616-620.

[11] LIU Chunsheng, REN Chunping. Reconstruction and deduction algorithm of the experimental load spectrum based on discrete regularization[J]. Chinese Journal of Applied Mechanics, 2014(4): 616-620(in Chinese).

[12] PARK J Y, KANG H, LEE J W, et al. A study on rock cutting efficiency and structural stability of a point attack pick cutter by lab-scale linear cutting machine testing and finite element analysis[J]. International Journal of Rock Mechanics and Mining Sciences, 2018, 103: 215-229.

[13] ZHAO X B, YAO X H, GONG Q M, et al. Comparison study on rock crack pattern under a single normal and inclined disc cutter by linear cutting experiments[J]. Tunnelling and Underground Space Technology, 2015, 50: 479-489.

[14] 廖九波, 李夕兵, 王少锋, 等. 截割厚度和截线距对镐型截齿破岩的影响研究[J]. 岩土力学, 2023， 44（4）: 1009-1021.

[15] LIAO Jiubo, LI Xibing, WANG Shaofeng, et al. Effects of cut depth and cut spacing on a conical pick in rock cutting[J]. Rock and Soil Mechanics, 2023, 44(4): 1009-1021(in Chinese).

[16] BILGIN N. Investigations into the mechanical cutting characteristics of some medium and high strength rocks[D]. Newcastle: Newcastle University, 1977.

[17] 蒋明镜, 孙亚, 陈贺, 等. 非贯通非共面节理岩体直剪试验DEM数值模拟[J]. 岩石力学与工程学报, 2015， 34（增刊2）: 3667-3675.

[18] JIANG Mingjing, SUN Ya, CHEN He, et al. Numerical simulation of direct shear tests for discontinuous and non-coplanar jointed rock masses using DEM[J]. Chinese Journal of Rock Mechanics and Engineering, 2015, 34(S2): 3667-3675(in Chinese).

[19] 唐志强, 李皋, 石祥超, 等. 岩石单轴冲击加载破碎特征分析[J]. 应用力学学报, 2019， 36（5）: 1076-1081.

[20] TANG Zhiqiang, LI Gao, SHI Xiangchao, et al. Analysis of rock fragmentation characteristics under uniaxial impact loading[J]. Chinese Journal of Applied Mechanics, 2019, 36(5): 1076-1081(in Chinese).

[21] YASAR S, YILMAZ A O. Rock cutting tests with a simple-shaped chisel pick to provide some useful data[J]. Rock Mechanics and Rock Engineering, 2017, 50(12): 3261-3269.

[22] YASAR S, YILMAZ A O. Drag pick cutting tests: a comparison between experimental and theoretical results[J]. Journal of Rock Mechanics and Geotechnical Engineering, 2018, 10(5): 893-906.

[23] 丁桐桐, 徐建华, 李远安, 等. 基于离散单元法的立轴冲击破碎机成砂率数值计算[J]. 应用力学学报, 2021， 38（5）: 2018-2024.

[24] DING Tongtong, XU Jianhua, LI Yuanan, et al. Numerical calculation of sand formation rate of vertical shaft impact crusher based on discrete element method[J]. Chinese Journal of Applied Mechanics, 2021, 38(5): 2018-2024(in Chinese).

[25] ROJEK J, OÑATE E, LABRA C, et al. Discrete element simulation of rock cutting[J]. International Journal of Rock Mechanics and Mining Sciences, 2011, 48(6): 996-1010.

[26] YANG Z, TAO M, RANJITH P G. Novel insights into grain size effect of stressed crystalline rock using weakened grain boundary model[J]. International Journal of Rock Mechanics and Mining Sciences, 2025, 189: 106098.

[27] YANG Z, TAO M, MEMON M B, et al. Microwave irradiation-induced deterioration of rock mechanical properties and implications for mechanized hard rock excavation[J]. Journal of Rock Mechanics and Geotechnical Engineering, 2025, 17(1): 275-290.

[28] SHI Y P, XIA Y M, TAN Q, et al. Distribution of contact loads in crushed zone between tunnel boring machine disc cutter and rock[J]. Journal of Central South University, 2019, 26(9): 2393-2403.

[29] 万国香, 王其胜, 李夕兵. 动静组合加载下花岗岩的力学性能[J]. 应用力学学报, 2010， 27（3）: 630-634.

[30] WAN Guoxiang, WANG Qisheng, LI Xibing. Mechanical properties of granite under coupled static-dynamic load[J]. Chinese Journal of Applied Mechanics, 2010, 27(3): 630-634(in Chinese).

[31] 万柯, 李锡夔. Biot-Cosserat连续体-离散颗粒集合体模型的非饱和土连接尺度方法[J]. 应用力学学报, 2013， 30（3）: 297-303.

[32] WAN Ke, LI Xikui. Bridging scale method for Biot-Cosserat continuum-discrete particle assembly modeling of unsaturated soil[J]. Chinese Journal of Applied Mechanics, 2013, 30(3): 297-303(in Chinese).

[33] 刘春, 乐天呈, 施斌, 等. 颗粒离散元法工程应用的三大问题探讨[J]. 岩石力学与工程学报, 2020， 39（6）: 1142-1152.

[34] LIU Chun, YUE Tiancheng, SHI Bin, et al. Discussion on three major problems of engineering application of the particle discrete element method[J]. Chinese Journal of Rock Mechanics and Engineering, 2020, 39(6): 1142-1152(in Chinese).

[35] LIU C, POLLARD D D, SHI B. Analytical solutions and numerical tests of elastic and failure behaviors of close-packed lattice for brittle rocks and crystals[J]. Journal of Geophysical Research (Solid Earth), 2013, 118(1): 71-82.

[36] LIU C. Matrix discrete element analysis of geological and geotechnical engineering[M]. Singapore: Springer Singapore, 2021.

[37] DAI F, WEI M D, XU N W, et al. Numerical investigation of the progressive fracture mechanisms of four ISRM-suggested specimens for determining the mode I fracture toughness of rocks[J]. Computers and Geotechnics, 2015, 69: 424-441.

[38] WU Z J, ZHANG P L, FAN L F, et al. Numerical study of the effect of confining pressure on the rock breakage efficiency and fragment size distribution of a TBM cutter using a coupled FEM-DEM method[J]. Tunnelling and Underground Space Technology, 2019, 88: 260-275.

[39] WEI M D, DAI F, XU N W, et al. Discussion on “a calibration methodology to obtain material parameters for the representation of fracture mechanics based on discrete element simulations”[J]. Computers and Geotechnics, 2017, 86: 246-248.

[40] LIU C, XU Q, SHI B, et al. Mechanical properties and energy conversion of 3D close-packed lattice model for brittle rocks[J]. Computers & Geosciences, 2017, 103: 12-20.

基金资助

国家自然科学基金资助项目(52474168)

国家自然科学基金资助项目(52174099)

湖湘青年英才资助项目(2023RC3050)