Indentation hardness and brittleness are the important factors to be considered in the study of rock-like materials’ mechanical crushing behaviors. The brittleness of rock-like materials is defined as the ratio of uniaxial compressive strength to tensile strength in this paper. In order to investigate the influences of hardness and brittleness on rock-like materials’ crushing behaviors, quartz sand and high strength α-hemi-hydrated gypsum were used to prepare rock-like materials with different hardness and brittleness through different mass ratios. The artificial rock-like materials can eliminate the effects of natural rock’s weak structure plane on experimental results. The indentation test, Uniaxial compressive test, and Brazilian tensile test were conducted for characterizing the indentation hardness and brittleness of this artificial rock-like materials. The experimental results showed that brittleness increased with the increase of indentation hardness with high correlation coefficient. The confining stress presented a positive impact on the indentation hardness of the rock-like materials. Based on those mechanical properties, the numerical rock models were calculated to study rock crushing behaviors using discrete element method (DEM). A series of rock crushing tests were conducted to investigate the influences of hardness and brittleness of rock-like materials on rock crushing behaviors using a conical pick cutter. The numerical results showed that the normalized specific energy was negatively correlated with indentation hardness index (IHI). The normalized specific energy decreased with the increase of brittleness index (BI) with a high correlation coefficient. This study is beneficial in utilizing IHI and BI to evaluate the mechanical properties, failure patterns, and mechanical crushing efficiency of rock-like materials.

中文翻译：

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研究岩石材料的压痕硬度和脆性对其机械破碎行为的影响

压痕硬度和脆性是研究类岩石材料的机械破碎行为时要考虑的重要因素。本文将岩石材料的脆性定义为单轴抗压强度与抗拉强度之比。为了研究硬度和脆性对岩石材料的破碎行为，石英砂和高强度α的影响用半水合石膏通过不同的质量比制备具有不同硬度和脆性的岩石状材料。人造岩石样材料可以消除天然岩石的弱结构面对实验结果的影响。进行压痕试验，单轴压缩试验和巴西拉伸试验以表征这种人造岩石状材料的压痕硬度和脆性。实验结果表明，脆性随压痕硬度的增加而增加，且相关系数较高。围压对岩石材料的压痕硬度产生积极影响。基于这些力学特性，计算了数值岩石模型，以使用离散元方法（DEM）研究岩石的破碎行为。进行了一系列的岩石破碎测试，以研究使用圆锥形截齿刀具的岩石状材料的硬度和脆性对岩石破碎行为的影响。数值结果表明，归一化比能与压痕硬度指数（IHI）负相关。归一化比能随脆性指数（BI）的增加而降低，且相关系数较高。这项研究有益于利用IHI和BI评估类岩石材料的机械性能，破坏模式和机械破碎效率。数值结果表明，归一化比能与压痕硬度指数（IHI）负相关。归一化比能随脆性指数（BI）的增加而降低，且相关系数较高。这项研究有益于利用IHI和BI评估类岩石材料的机械性能，破坏模式和机械破碎效率。数值结果表明，归一化比能与压痕硬度指数（IHI）负相关。归一化比能随脆性指数（BI）的增加而降低，且相关系数较高。这项研究有益于利用IHI和BI评估类岩石材料的机械性能，破坏模式和机械破碎效率。