摘要
为了研究土-结构接触界面各种微观参数对宏观响应的影响,从土的细观结构出发,采用二维离散元法进行双轴剪切数值试验,对颗粒间摩擦因数、颗粒形状、孔隙比、法向应力以及刚度比等参数进行灵敏度分析,得出各种微观参数对宏观响应的影响,建立接触界面颗粒材料微宏观参数的跨尺度关联,揭示接触界面处的颗粒材料力学行为的细观机理.结果表明:摩擦因数、孔隙比、颗粒形状和法向应力对接触界面的峰值强度影响较大,刚度比对接触界面的峰值强度影响较小;摩擦因数、法向应力和刚度比对弹性模量影响显著,其中摩擦因数与内摩擦角近似成正比,且对土体的抗剪强度和剪胀性影响较大.组合圆弧颗粒比圆形颗粒更接近真实砂粒形状,模拟效果更好;其临界强度和临界孔隙比不受初始孔隙比的影响,且组合圆弧颗粒体的抗剪强度受法向应力影响,法向应力越大,颗粒体抗剪强度越大.研究结果为接触界面的材料优化、改性等提供理论参考.
In order to study the effect of various micro parameters of the soil-structure contact interface on the macro response,starting from the meso structure of the soil,a two-dimensional discrete element method is used to conduct a biaxial shear numerical test.The sensitivity analysis is carried out for the friction coefficient,particle shape,void ratio of the particles,normal stress,stiffness ratio and other parameters.The influence of various micro parameters on the macro response is found.It also establishes a cross-scale correlation of the micro-macro parameters of the granular material at the contact interface,and reveals the meso-mechanical behavior of the granular material at the contact interface mechanism.The results show that friction coefficient,porosity ratio,particle shape and normal stress have a greater influence on the peak strength of the contact interface,stiffness ratio has a smaller influence on the peak strength of the contact interface;friction coefficient,normal stress and stiffness ratio have an influence on the elastic modulus.The effect is significant,in which the friction coefficient is approximately proportional to the internal friction angle,and it has a greater impact on the shear strength and shear dilatancy of the soil.The combined arc particles are closer to the true sand shape than the round particles,and the simulation effect is better.The critical strength and critical porosity ratio are not affected by the initial porosity ratio and the shear strength of the combined arc particles is affected by the normal stress.The greater the normal stress,the greater the shear strength of the particles.The research results provide a theoretical reference for material optimization and modification of the contact interface.
作者
王桂萱
鞠碧玉
秦建敏
WANG Guixuan;JU Biyu;QIN Jianmin(Centre for Research and Development of Civil Engineering Technology,Dalian University,Dalian 116622,China)
出处
《扬州大学学报（自然科学版）》
CAS
北大核心
2020年第3期44-50,共7页
Journal of Yangzhou University：Natural Science Edition
基金
国家自然科学基金资助项目(51678100)
辽宁省自然科学基金资助项目(2015020225)
辽宁省工业攻关及产业化指导计划资助项目(2019JH8/10100090).
关键词
离散元法
颗粒材料
接触界面
宏细观参数
discrete element method
granular materials
interface
macro-micro parameters
