Coupled two-dimensional discrete element and multibody dynamic modeling for interaction of the soil and rough shaped rigid bodies  

土壤与粗糙刚体相互作用的二维离散元多体耦合动力学建模

作　　者：Ning Ding Jinyang Liu Caishan Liu 丁宁;刘锦阳;刘才山(Department of Engineering Mechanics,School of Naval Architecture,Ocean and Civil Engineering,Shanghai Jiao Tong University,Shanghai,200240,China;State Key Laboratory of Turbulence and Complex System,College of Engineering,Peking University,Beijing,100871,China)

机构地区：[1]Department of Engineering Mechanics,School of Naval Architecture,Ocean and Civil Engineering,Shanghai Jiao Tong University,Shanghai,200240,China [2]State Key Laboratory of Turbulence and Complex System,College of Engineering,Peking University,Beijing,100871,China

出　　处：《Acta Mechanica Sinica》2022年第7期148-163,I0004,共17页力学学报（英文版）

基　　金：supported by the Key Program of National Natural Science Foundation of China(Grant No.11932001);the General Program of National Natural Science Foundation of China(Grant Nos.11772186 and 11772188);for which the authors are grateful.This research was also supported by the Key Laboratory of Hydrodynamics(Ministry of Education).

摘　　要：The study of soil and rigid body system interactions is very important for the exploration of the Moon and Mars worldwide.The discrete element method(DEM)is a relatively accurate simulation method to study dry sand soil mechanical properties.However,it is not suitable for bodies that are in mutual contact,connected due to constraints or have complex inertia properties due to their geometry.An efficient combination of the two-dimensional discrete element and multibody dynamic modeling method is proposed to solve the problem,in which the contacts and frictions among the granular spheres and the multibody system,including the smooth and rough rigid bodies,are taken into account.In this work,the soil field is modeled by a two-dimensional DEM,and the dynamics of the constrained rigid body system are modeled by the Cartesian method.A detection algorithm is developed to address the interactions between spherical discrete elements and roughly shaped rigid bodies.The advantage of this coupled method is that it enables the simultaneous capture of both responses.Finally,the program is verified by simulation experiments of the three-ball collision and the collision among the rectangular bars and the three balls.Based on this,the movement of the toothed wheel in the granular matter is analyzed,and the results show that the wheel with six teeth and 30°inclination has the fastest forward speed.In extraterrestrial objects,the wheel grip worsens,but the forward speed first increases and then decreases with decreasing gravity acceleration and loads on wheels,which proves that the coupled two-dimensional DEM and multibody dynamic program is effective in solving engineering problems.土壤与刚体系统相互作用的研究是世界各国探索月球和火星的一项重要工作.为了研究干沙土的力学性质,离散单元法(DEM)是一种比较精确的模拟方法.但它不适用于相互接触、因约束而连接或因几何结构而具有复杂惯性特性的物体.为解决这一问题,文章提出一种二维离散元多体动力学建模方法,该方法考虑了颗粒球与包括光滑刚体和粗糙刚体在内的多体系统之间的接触和摩擦.在这项工作中,土壤场采用二维DEM建模,约束刚体系统的动力学采用笛卡儿方法建模.针对球形离散单元和粗糙刚体之间的相互作用提出一种检测算法.此耦合方法的优点是能够同时捕获两个响应.最后通过三球碰撞和矩形杆与三球碰撞的仿真实验,验证了程序的正确性.在此基础上,对齿轮在颗粒物中的运动进行了分析,结果表明,六齿30°倾角的齿轮具有最快的前进速度.在地外物体中,车轮抓地力变差,但随着重力加速度和车轮载荷的减小,前进速度先增大后减小,这证明了耦合二维DEM和多体动力学程序在解决工程问题中的有效性.

关 键 词：Discrete element method Multibody dynamic system Rough-shaped rigid body Toothed wheel in granular matter 

分 类 号：S152.9[农业科学—土壤学]