不同级配颗粒材料的循环硬化行为与能量耗散  

CYCLIC HARDENING BEHAVIOR AND ENERGY DISSIPATION OF GRANULAR MATERIALS WITH DIFFERENT PARTICLE SIZE DISTRIBUTIONS

作　　者：夏平心 邓文 邵龙潭[3] XIA Pingxin;DENG Wen;SHAO Longtan(School of Urban Construction,Changzhou University,Changzhou 213164,China;School of Civil Engineering,Southeast University,Nanjing 211189,China;Department of Engineering Mechanics,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]常州大学城市建设学院,常州213164 [2]东南大学土木工程学院,南京211189 [3]大连理工大学工程力学系,大连116024

出　　处：《工程地质学报》2022年第5期1485-1493,共9页Journal of Engineering Geology

基　　金：中央高校基本科研业务费专项资金(资助号:3205002212A1);江苏特聘教授科研资助经费(资助号:1105000492).

摘　　要：颗粒材料在循环荷载作用下呈现循环硬化行为,然而关于循环硬化行为的宏-微观相对应的机理解释的研究却不多见。本文通过3D-DEM实施了循环三轴数值模拟试验,研究了不同级配下颗粒材料在循环荷载下的循环硬化行为,并分析了(轴向)平均模量和由滑动接触造成的能量耗散的演化趋势。结果表明随着循环荷载的进行,平均模量逐渐增加并趋于渐进值。每个循环内的能量耗散随着循环数的增加不会一直衰减,存在一个阈值。不同颗粒级配下平均模量的增加指数和能量耗散衰减指数的大小相近(约为0.6),表明在描述循环荷载硬化行为时,无论是使用变形模量还是归一化能量耗散在结果上是一致的,即微观尺度上滑动接触引起的能量耗散映射出宏观尺度上平均模量的变化。颗粒平均粒径越大的颗粒体系,其平均模量越大,而且越早完成能量耗散过程,但不同的颗粒级配下对应的能量耗散阈值差异较小,基本上维持在一个常数(约为0.15)。Granular materials exhibit cyclic hardening behavior under cyclic loading.However,there are few studies on the mechanistic explanation of cyclic hardening behavior at the macro-micro scale.In this paper,the cyclic triaxial test DEM simulation is carried out to study the cyclic hardening behavior of granular materials with different particle size distribution under cyclic loading.The evolution of(axial)average deformation modulus and energy dissipation due to sliding contact is analyzed.The results show that the average modulus increases gradually and tends to asymptotic values as the cyclic loading progresses.The energy dissipation of each cycle does not always decay with the increase of cycles,but has a threshold.The increase index of the average modulus and the decay index of energy dissipation are similar in magnitude(about 0.6)for all the specimens with different particle size distribution,indicating that whether the deformation modulus or the normalized energy dissipation are used,the results are consistent when describing the cyclic hardening behavior.The energy dissipation caused by sliding contact at the microscale is mapped to the average modulus at the macroscale.The larger the average particle size of the granular assembly,the larger the average modulus,and the earlier the completion of the energy dissipation process.However,the corresponding energy dissipation threshold difference under different particle size distributions is small,basically maintained at a constant of 0.15.

关 键 词：变形模量 滑动接触 能量耗散 循环荷载 3D-DEM 颗粒材料 

分 类 号：P642.3[天文地球—工程地质学]