摘要
基于颗粒微观力学的方法建立了高阶应力-应变理论的损伤本构模型,并采用无网格伽辽金方法建立的离散化的数值模型对静载荷作用下的平底圆柱型压头压入花岗岩的变形(直至破碎)的过程进行了模拟分析。结果表明,最大剪应力分布云图以及破碎坑深度均与相关文献的研究结果基本吻合,验证了模型的合理性和有效性;在静压入过程中花岗岩模型表现出了明显的应变局部化现象,表明花岗岩是1种典型的应变软化材料;花岗岩内部的应力极限值总是集中在压头与岩石接触的边缘位置;中心对称轴上的最大剪应力极值点是岩石破碎的发源处;随着压头的逐渐压入,花岗岩内水平向的拉应力先于剪应力达到极限值,迫使周围的岩石发生崩离,导致张拉断裂。
A damage constitutive law of higher-order stress-strain theory was established based on granular micromechanics method,combing with a discrete numerical model via element-free Galerkin method,to simulate and analyze the deformation and fragmentation process of granite under static loading induced by flattened cylindrical indenter.The results indicate that the distribution of maximum shear stress and the crater depth are consistent with the results of related literatures,which proves the rationality and validity of the model.In the process of static indentation,the granite model shows obvious strain localization,which indicates that granite is a typical strain softening material.The internal maximum stress of granite always concentrates on the edge of indenter in contact with the rock.The maximum stress point on the central axis of symmetry is the initiation place of rock fragmentation.With the gradual increase of indentation depth,the horizontal tensile stress in granite firstly reaches its limit,forcing the collapse of surrounding rock and leading to tensile fracture.
出处
《中国科技论文》
北大核心
2017年第9期1024-1029,1043,共7页
China Sciencepaper
基金
高等学校博士学科点专项科研基金资助项目(20130145120004)
国家自然科学基金资助项目(51309208
50904052)
中国地质大学(武汉)"摇篮计划"资助项目(CUG140418)
关键词
岩石破碎
微观力学
静载荷
无网格伽辽金法
高阶理论
rock fragmentation
micromechanics
static loading
element-free Galerkin method
higher-order theory
