| 基于力链的岩石单齿截割特性研究及截割力预测 |
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| 引用本文： | 董磊,张华,吕继双,石瑞敏.基于力链的岩石单齿截割特性研究及截割力预测[J].岩土力学,2022,43(11):3036-3046. |
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| 作者姓名： | 董磊 张华 吕继双 石瑞敏 |
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| 作者单位： | 1. 中北大学 机械工程学院，山西 太原 030051；2. 煤矿采掘机械装备国家工程实验室，山西 太原 030032；
3. 中国煤炭科工集团太原研究院，山西 太原 030006 |
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| 基金项目： | 国家自然科学基金（No. 51875152）；山西省基础研究计划项目（No. 20210302123065）；天地科技股份有限公司重点项目（No. KY202054）。 |
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| 摘 要： | 截齿是煤矿采掘机械上截割工作的主要承载对象，其与工作面的截割力预测对减小截齿磨损十分重要。利用颗粒流仿真软件PFC2D将被截割岩石作为颗粒物质进行单齿截割模拟仿真，通过研究截割时颗粒间力链的特性探讨了单齿截割岩石时接触状态对截割力的影响。利用单齿截割岩石试验台进行了截割力试验，获得了截割法向力和切向力随截割参数的变化规律及掉落碎片的特征。研究结果表明，单齿截割岩石颗粒物质的力链数目与力链长度的关系符合单轴压缩试验结果，能够采用离散元的方法对截齿截割状态进行模拟。力链网络沿着点接触方向扩散并延长，力链方向与截割角度有关，平均法向力方向呈“花生”状，切向力方向呈“花瓣”状。力链数目随截割角度的减小和截割深度的增加而减少，力链长度随截割距离的增加而增加，最大平均长度为8个颗粒尺寸。当截割角度较大时，较为容易形成力链。单齿截割天然砂岩法向力和切向力随截割角度的增加和截割深度的减小而减小。截割碎片尺寸与截割切向力线性拟合度为0.87。基于力链长度的截割力预测模型相比Evans预测模型法向力精度提高了17.6%，切向力精度提高了16.9%。研究结果能够为截齿和采掘机械截割系统的设计以及截割工艺的优化奠定一定的研究基础。
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| 关 键 词： | 颗粒物质 单齿截割 力链 力预测 |
| 收稿时间： | 2022-01-05 |
| 修稿时间： | 2022-07-13 |
Rock cutting characteristics with single pick and prediction
of cutting force based on force chain |
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| DONG Lei,ZHANG Hua,Lü Ji-shuang,SHI Rui-min.Rock cutting characteristics with single pick and prediction
of cutting force based on force chain[J].Rock and Soil Mechanics,2022,43(11):3036-3046. |
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| Authors: | DONG Lei ZHANG Hua LÜ Ji-shuang SHI Rui-min |
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| Institution: | 1. School of Mechanical and Power Engineering, North University of China, Taiyuan, Shanxi 030051, China;
2. National Engineering Laboratory of Coal Mining Machinery Equipment, Taiyuan, Shanxi 030032, China;
3. Taiyuan Institution, China Coal Technology and Engineering Group, Taiyuan, Shanxi 030006, China |
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| Abstract: | The pick is the main load-bearing object of the mining machinery for cutting coal, and the prediction of the cutting force from the working face is very important to reduce the wear of the pick. The rock was considered as a particle matter for single pick cutting simulation by using the particle flow code (PFC2D). The influence of the contact state on the cutting force of the single pick was discussed by studying the characteristics of the interparticle force chain during cutting. The cutting force test was carried out on a single pick cutting rock test equipment, and the changing law of normal and tangential force with cutting parameters and the characteristics of falling fragments were obtained. The research results show that the relationship between the number of force chains and the length of the force chains for rock particles cut by a single pick is consistent with the uniaxial compression test results, and the cutting state of the single pick can be simulated by using discrete element method. The force chain network spreads and extends along the point contact direction, which is related to the cutting angle. The average normal force direction is "peanut"-like whereas the tangential force direction is "petal"-like. In addition, the number of force chains decreases with the decrease of cutting angle and the increase of cutting depth. The length of force chains increases with the increase of cutting distance. The maximum average length is about 8 particle sizes. The force chains tend to form at larger cutting angles. Furthermore, the normal force and tangential force of single pick cutting of natural sandstone decrease with the increase of cutting angle and the decrease of cutting depth. The linear correlation between the size of the cutting fragments and the cutting tangential force is 0.87. Compared with the Evans prediction model, the accuracy of normal force and tangential force based on force chain length is improved by 17.6% and 16.9% respectively. The research results lay a certain research foundation for the design of cutting pick, mining machinery cutting system and the optimization of cutting technology. |
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| Keywords: | granular material single pick cutting force chain force prediction |
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