垂直振动下干湿颗粒样品的体积模量与耗散  

Experimental study on bulk modulus and dissipation of dry and wet granular samples under vertical vibration

作　　者：杜清馨 孙其诚[2] 丁红胜[1] 张国华[1] 范彦丽 安飞飞 Du Qing-Xin;Sun Qi-Cheng;Ding Hong-Sheng;Zhang Guo-Hua;Fan Yan-Li;An Fei-Fei(Department of Physics,University of Science and Technology Beijing,Beijing 100083,China;State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]北京科技大学物理系,北京100083 [2]清华大学,水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《物理学报》2022年第18期245-252,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:91634202,11972212)资助的课题。

摘　　要：研究了垂直振动条件下,干、湿玻璃珠样品的体积模量和相对耗散.实验发现:1)在低饱和度下,干、湿玻璃珠样品的体积模量随压强幂律变化,与基于赫兹接触势的有效介质理论预言的1/3幂律关系接近;加入少量液体会增加体积模量.同一压强和液体含量下,随着液体黏度的增大,体积模量随之增加.基于赫兹接触力学,提出了有效弹性网络模型来阐述湿玻璃珠样品体积模量的增加机制.2)干、湿玻璃珠样品的相对耗散随压强幂律降低,湿玻璃珠样品的相对耗散与液体黏度呈正比.3)随着应变幅值的增大,湿玻璃珠样品表现出类似干玻璃珠样品的软化行为,且液体黏度会抑制玻璃珠样品的软化行为.Dry granular materials are composed of a dense random packing of macroscopic grains.As a small amount of liquid is added to granular samples,the liquid bridge forces,i.e.the forces between liquid and the grains,have an influence on the mechanical properties of wet granular material,and some of these properties are quite different from those of dry granular materials.In this work,by measuring the acceleration of the sample chamber and the force exerted on it by the shaker,the variations of bulk modulus and energy dissipation of both dry and wet glass bead samples with pressure and viscosity under vertical vibration are studied.The results are shown below.1)Under low saturation,the bulk modulus of dry and wet glass bead sample are both described by a power law scaling law with pressure,which is close to the power law relationship predicted by the efficient medium theory on the basis of Hertz contact potential.A small amount of liquid can increase the bulk modulus of glass bead sample.At the same pressure and liquid content,the bulk modulus of wet glass bead sample increases with liquid viscosity increasing.Based on Hertzian contact mechanics,an efficient elastic network model is proposed to illustrate the mechanism of increasing bulk modulus of wet glass bead samples.2)The energy dissipation of dry and wet glass bead sample decrease following the power law of pressure,and the energy dissipation of wet glass bead samples is proportional to the kinematic viscosity of liquid.3)With the increase of strain amplitude,the softening behavior of the wet glass bead sample is similar to that of the dry glass bead sample,when the strain amplitude is higher than the strain threshold value.The kinematic viscosity of liquid inhibits the softening behavior of glass bead sample.

关 键 词：颗粒物质 体积模量 能量耗散 液桥力 

分 类 号：O347.7[理学—固体力学]