预设V形缺口的单向拉伸岩样变形-开裂过程模拟——基于连续-非连续方法  

Modeling of Deformation-cracking Processes of Rock Specimens with V-shaped Notches in Uniaxial Tension——Based on a Continuum-discontinuum Method

作　　者：王学滨 陈忠元[2] 郭瑞 郭翔[2] 芦伟男[2] WANG Xuebin;CHEN Zhongyuan;GUO Rui;GUO Xiang;LU Weinan(Institute of Computational Mechanics, Liaoning Technical University, Fuxin 123000, China;College of Mechanics and Engineering, Liaoning Technical University, Fuxin 123000, China)

机构地区：[1]辽宁工程技术大学计算力学研究所,辽宁阜新123000 [2]辽宁工程技术大学力学与工程学院,辽宁阜新123000

出　　处：《防灾减灾工程学报》2018年第2期209-215,共7页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金项目(51574144);辽宁省百千万人才项目(2017)资助

摘　　要：利用自主开发的连续-非连续方法,通过在岩样左、右两侧预设V形缺口,开展了拉伸位移控制加载条件下岩样变形-开裂过程的数值模拟研究。研究发现：在节点分离前,最大主应力集中于V形缺口尖端附近;在节点分离后,最大主应力集中于裂缝尖端附近;岩样中节点分离是由外及里逐渐发生;由于岩样内部一定尺寸弹性核心的存在,即使岩样发生少许节点分离,岩样承载能力也不会下降,但刚度会劣化;在节点分离不久,分离节点的法向张开度和法向力均呈现一定的非线性,这可能与分离节点周围单元应力分布不均匀和未考虑切向力等因素有关;网格加密后,V形缺口的尺寸相应降低,这导致载荷-位移曲线的峰值提升,该曲线的峰前和峰后部分变陡;分离节点的法向张开度和法向黏聚力随时间的演变曲线几乎不存在网格依赖性。对文中的多种数值结果的正确性进行了检验。A continuum-discontinum method developed by the authors is used to numerically simulate the deformation-cracking processes of rock specimens with V-shaped notches in displacementcontrolled uniaxial tension tests.The following results are found.Prior to and beyond the nodal separation,the maximum principal stresses are concentrated at tips of notches and cracks.Separation of nodes in rock specimens is from the outside to the inside.If an elastic core with a certain size appears,the load-bearing capacity of the specimen may not decrease,but the stiffness decreases because several nodes have separated in the specimen.Shortly after nodes separated,normal forces and normal opening displacements of separating nodes exhibit non-linearity,which is possibly related to the nonuniform distribution of stress around the separating nodes and the neglect of the tangential force.After the mesh is refined,the maximum load-bearing capacity of the specimen increases and the pre-peak and post-peak parts of the load-displacement curve become steep.Normal force-time curves and normal opening displacement-time curves are almost size-independent.Numerical results are verified on several aspects.

关 键 词：单向拉伸 网格依赖性 V形缺口 开裂过程 载荷—位移曲线 

分 类 号：U442.5[建筑科学—桥梁与隧道工程]