摘要
细观参数的正确选取是离散元模拟成功的关键,然而,目前细观参数的选取具有一定的人为性和不确定性,导致分析结果的不可比性。利用颗粒材料单元体宏观力学参数和颗粒细观参数间的相关性,通过室内三轴试验的PFC3D模拟和结果的回归分析,基于线性接触模型建立了颗粒材料初始杨氏模量、初始泊松比等宏观弹性常数与颗粒法向刚度、颗粒刚度比等细观弹性常数间的经验公式。研究结果表明:对于线性接触模型,颗粒材料的初始杨氏模量和剪切模量约与围压的1/10次方成正比,并约与颗粒粒径的0.9次方成反比。初始泊松比则约与颗粒刚度比的1/14次方成正比,而与颗粒粒径几乎无关。常见砂土的颗粒刚度比为2.0～20.7。
For the discrete element method（DEM）,the key to a successful simulation lies in proper micro-parameters.However,the current way to select micro-parameters is often subjective and unreliable,resulting in incomparability among different simulations.Based on the linear contact model,a set of empirical formulas are presented to describe the correlation between macroscopic elastic constants of granular materials and microscopic elastic constants of particles by simulating tri-axial tests with PFC3D and through regression analysis of numerical results.The macroscopic elastic constants include the initial Young’s modulus and the initial Poisson’s ratio,and the microscopic elastic constants include the normal stiffness,stiffness ratio of particle,etc.It is found that the initial Young’s modulus and the shear modulus are approximately proportional to one tenth power of the confining pressure,and inversely proportional to nine tenths power of the particle size.The initial Poisson’s ratio is approximately proportional to one fourteenth power of the stiffness ratio of the particle for the linear contact model,and almost independent of the particle size.It is also found that the rational stiffness ratio of the particle ranges from 2.0 to 20.7 for the common sand.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2010年第7期991-998,共8页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(50778163
50708095)
国家"973"重点基础研究课题(2007CB714200)
地震行业专项基金项目(200808022)
关键词
线性接触模型
细观弹性常数
宏观弹性常数
颗粒刚度比
颗粒粒径
相关关系
linear contact model
microscopic elastic constant
macroscopic elastic constant
stiffness ratio of particle
particle size
correlation
