摘要
建立随机均布Voronoi图的生成算法,以这种网格划分方式作为刚块弹簧元法(RBSM)的基本计算网格。同时,将刚体弹簧方法的界面中点接触模型改为整个界面的均布接触模型,结合界面抗拉强度和莫尔–库仑准则,给出一个能同时考虑模式Ⅰ和Ⅱ的断裂破坏的界面破坏模型。大量数值试验表明,以随机Voronoi图为基本计算网格,块体平均尺寸和排列方式对宏、细观弹性参数之间的关系影响很小,从而克服了颗粒离散元法的网格依赖性和宏、细观参数繁琐的标定程序。将该数值模型计算结果与Vienne岩石试验结果对比,数值模拟结果与试验结果在变形和强度都吻合较好,且随着围压的增大,应力–应变曲线的峰后下降趋势逐渐放缓,在围压为40 MPa时接近水平,表现出明显的由脆性向延性过渡的趋势。
A numerical procedure is developed to generate randomly and uniformly distributed Voronoi diagram, which is used as the basic mesh for rigid body spring method(RBSM). The midpoint contact model of original RBSM is modified into distributed interface contact model. A fracture criterion is proposed through combining Mohr-Coulomb law and tension strength,which can account for mode I and mode II fracturing at the same time. It is found from a series of numerical tests that mesh size and mesh arrangement have little effects on the relationship between macro and meso elastic parameters. A fitting relation is given to overcome the problem of mesh dependency of particle discrete element method and to simplify the complex calibration procedure of which for macro-meso parameters identification. Comparison with Vienne rock experiments shows that both strength and deformation analyzed by the proposed model are in good agreement with the experiment data. Thus,the validity of the proposed model is verified.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2013年第S2期3146-3153,共8页
Chinese Journal of Rock Mechanics and Engineering
基金
国家重点基础研究发展计划(973)项目(2010CB732005)
国家自然科学基金资助项目(51179137)
