往复荷载下铁路道砟沉降特性的扩展多面体离散元分析  

Dilated Polyhedral Discrete Element Analysis of Settlement Characteristics of Railway Ballast under Cyclic Loading

作　　者：孙珊珊[1] 严颖[2] 赵春发[3] 季顺迎[1] 

机构地区：[1]大连理工大学工业装备结构分析国家重点实验室,辽宁大连116023 [2]大连交通大学土木与安全工程学院,辽宁大连116028 [3]西南交通大学牵引动力国家重点实验室,四川成都610031

出　　处：《铁道学报》2015年第11期89-95,共7页Journal of the China Railway Society

基　　金：国家自然科学基金(11172063;U1234209)

摘　　要：基于Minkowski Sum方法,采用扩展多面体单元构造非规则的道砟颗粒,对道砟材料在往复荷载作用下的动力特性进行离散元分析,研究其沉降量和形变刚度的演变过程。结果表明,在往复荷载作用下道砟材料的累计沉降量在变形初期增加显著,随着往复荷载次数的增加趋于稳定,其有效刚度在累计变形过程中不断增大并最终趋于平稳。本文研究表明,扩展多面体单元可有效模拟道砟材料的力学行为,研究其在列车往复荷载下的动力特性。Based on the Minkowski Sum method, this paper introduced dilated polyhedral element to describe the irregular geometry of ballast particles and conducted discrete element analysis on the dynamic characteristics of ballast material under cyclic loading to study the evolution of the settlement and deformation stiffness of ballast material. The results showed that the accumulative settlement of ballast material under cyclic loading increased significantly at the early stage of deformation and then tended to be stable with the increase of the fre- quency of cyclic loading. Meanwhile, the effective stiffness during the accumulative deformation process of bal- last material also increased continuously and eventually became stable. Thus, this dilated polyhedral element can model the mechanic behaviors of ballast material effectively and reveal its dynamic characteristics under cyclic loading of train.

关 键 词：铁路道砟 离散单元法 扩展多面体单元 道砟箱试验 累计沉降量 变形模量 

分 类 号：U213.72[交通运输工程—道路与铁道工程]