基于颗粒离散元岩石模型的熵变规律研究

Study on Entropy Change Law Based on Particle Discrete Element Rock Model

以岩石单轴压缩试验为基础,借助离散元软件PFC 2D建立岩石破坏的数值模型,将熵变曲线与试样的应力应变曲线、裂缝数量及能量曲线等进行对比分析,以便研究岩石破坏时的熵变规律。结果表明,岩石在破坏过程中,微裂隙的产生会造成熵值的下降;岩石在峰值应力点破坏时,熵值曲线会有明显的下降趋势;在不同围压条件下,高围压试样的初始熵值较高。因此,以熵变规律分析岩石的破坏过程,对岩石的破裂演化具有诊断评价和辅助判断的作用。

Based on the uniaxial rock compression test, numerical model of rock failure was established in Particle Flow Code 2D, a discrete element method software. The entropy curve and the stress strain curve, the number of cracks and the energy curve were compared and analyzed so as to study the entropy changing law of rock failure. The results show that in the process of rock destruction, the generation of microcracks can cause the decline of entropy; Rock is destroyed at the peak stress point, 〖JP2〗and the curve of entropy will have a significant decline; Under different confining pressures, the initial entropy value of high confining pressure sample is higher. Therefore, analysis of rock failure process with the law of entropy variation has the functions of diagnostic evaluation and auxiliary judgment for the facture evolution of rock.〖JP〗