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在全断面岩石掘进机(TBM)刀具破岩的颗粒元模拟中颗粒参数的选取至关重要,其中颗粒间平行黏结切向、法向强度是关键控制性参数之一,它们之间的比值关系直接决定所模拟试样的延脆性质,影响刀具破岩过程及其破岩效果。为探讨延脆性对刀具破岩模式的影响,(1)建立9种采用不同平行黏结强度比值的数值模型,分别进行单轴压缩及巴西劈裂模拟研究不同延脆性试样的力学行为及破坏模式的变化。(2)对9种模型进行双刀破岩,并监控其裂缝的发展情况及刀具的受力状况。(3)为减小随机性对模拟结果的影响,通过改变随机数,每种模型重复模拟5次,综合分析5次的计算结果。模拟分析发现,随着切向和法向黏结强度比值(τ_c/σ_c)的增大,试样的脆性增加,破坏模式逐渐从剪切破坏转变为脆性张拉破坏,刀具破岩压碎区范围减小,张拉裂缝更容易在刀具间贯通延伸从而切割出块体更大的岩渣;随着试样脆性的增加,归一化比能减小,刀具破岩的效率增加;平行黏结强度比值相同的条件下采用不同随机数种子生成的模型中,试样的具体破坏情况有一定的差别,但总体破坏模式相似。
It is very important to select the parameters of the particles in the granule element simulation of rock breaking by TBM tool. Among them, the particles are parallel to each other and the normal strength is one of the key control parameters. The ratio between them Directly determine the delayed nature of the simulated specimen, affecting the tool breaking rock process and rock breaking effect. In order to investigate the influence of ductility on the rock breaking mode of the tool, (1) Nine numerical models with different ratios of parallel bond strengths were established. Uniaxial compression and Brazilian split simulation were carried out to study the mechanical behaviors and failure modes The change. (2) Double-rock the nine models and monitor the development of the cracks and the stress conditions of the tools. (3) In order to reduce the impact of randomness on the simulation results, by repeating the random number, each model was simulated 5 times repeatedly, and the results of 5 times were comprehensively analyzed. The simulation results show that the brittleness increases with the increase of the ratio of tangential to normal bond strength (τ_c / σ_c), and the failure mode gradually changes from shear failure to brittle tension failure. It is easier to cut through and extend between the cutting tools so as to cut larger rock fragments. With the increase of brittleness, the normalized specific energy can be reduced and the efficiency of rock breaking can be increased. The parallel bond strength In the same ratio of the same conditions using different random number seed generation model, the specific damage of the sample have some differences, but the overall destruction of similar patterns.