岩土力学2017，Vol.38Issue(5)：1472-1480,9.DOI:10.16285/j.rsm.2017.05.030
抗转动特性对颗粒材料分散性失稳的影响研究
Impact of rotation resistance on diffuse failure of granular materials
摘要
Abstract
Under the certain strain path,granular materials may exhibit non-localized failure mode corresponding to an abrupt occurrence of failure with the stress states within the Mohr-Coulomb yielding surface.Using the discrete element method (DEM),mechanical properties of granular material with different rolling friction coefficients are examined under proportional strain loading paths.For particle assemblies of different densities,looser assemblies tend to have diffuse failure,which qualifies Hill's second-order work criterion.A contact model considering rolling friction is adopted in DEM analysis.By changing the rolling friction coefficient,micro-macro mechanical properties of particle assembly are studied under a specific proportional strain-loading path.The enhancement of particle rolling resistance reduces the likelihood of diffuse failure.At the macro level,stress path changes from strain softening to strain hardening as the rolling friction coefficient increases,and the looser particle assembly exhibits the similar mechanical behaviours as the denser one.The micro-structure shows the corresponding mechanism of action.As the rolling friction coefficient increases,the angular velocities of particles and their distribution will be well controlled.Although the coordination number decreases,the contact forces are enhanced,and the instabilities and anisotropies of the force chain distribution can be improved in the system.All the microscopic parameters manifest a stable structure,which can resist the increasing load,thus the specimen will not form a loose contact state and diffuse failure will not occur.关键词
离散元/抗转动特性/分散性失稳/等比例应变加载/细观机制Key words
discrete element/rolling resistance characteristics/diffuse failure/proportional strain path/microscopic mechanism分类
建筑与水利引用本文复制引用
刘嘉英,马刚,周伟,常晓林..抗转动特性对颗粒材料分散性失稳的影响研究[J].岩土力学,2017,38(5):1472-1480,9.基金项目
国家自然科学基金青年基金项目(No.51509190) （No.51509190）
国家自然科学基金面上项目(51579193) （51579193）
中国博士后科学基金面上资助(No.2016T90727).This work was supported by the National Natural Science Foundation of China (51509190,51579193),the China Postdoctoral Science Foundation (2016T90727). （No.2016T90727）
