首页|光滑粒子法中的摩擦接触算法及其在含界面土体变形问题中的应用

光滑粒子法中的摩擦接触算法及其在含界面土体变形问题中的应用

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光滑粒子流体动力学(smoothed particle hydrodynamics,简称SPH)方法作为拉格朗日型的无网格粒子类方法,在固体极大变形问题的数值求解分析中具有显著优势.针对包含界面接触的固体大变形问题的SPH模拟,基于一种能改善边界精度的光滑粒子插值格式——有限粒子法(finite particle method,简称FPM),提出了一种新的点对体积的离散(point-to-volume discretization,简称PTVD)界面接触算法.该算法实际是将界面接触力等价转换为接触点附近两组粒子间的外部相互作用力.具体是根据接触界面特点将接触面两侧物体离散后的粒子划分为主体粒子和从属粒子,对于每个接触点附近的从属粒子,根据其影响域所包含的主体粒子情况确定该粒子与接触面的相对关系计算法向接触力,根据其影响域内两类粒子的相对切向速度和界面摩擦系数计算切向接触力.PTVD接触算法可避免界面粒子识别及精确模拟等相关的复杂接触力计算,充分体现了光滑粒子法的非局部特点.在利用经典界面接触和摩擦算例进行验证的基础上,将PTVD算法应用于颗粒土拟静力坍塌和弹体侵彻软土等涉及接触界面的大变形土力学问题SPH数值分析,结果表明PTVD算法在摩擦接触问题的SPH-I数值分析中具有有效性和广泛适用性.
A frictional contact algorithm in smoothed particle method with application in large deformation of soils
Smoothed particle hydrodynamics(SPH)is a Lagrangian meshless method,which has remarkable advantages in numerical analysis of solids with extremely large deformation.The present paper deals with SPH simulation of large solid deformation involving frictional contact interface.A new pure smoothed particle PTVD(point-to-volume discrete)contact algorithm is developed based on the FPM(finite particle method)particle interpolation,which is an alternative SPH formulation for improving the interpolation accuracy near boundaries.The PTVD contact algorithm transforms equivalently the interface contact force into the external interactive forces between particles near the contact interface.To be specific,the particles modelling either body in contact are grouped as master particles and slave particles with respect to the feature of the contact interface.For each slave particle near the contact point,the relative position is determined according to the amount of master particles contained in the influence domain of that particle,and the normal contact force is then calculated considering the contact stiffness.The shear contact force is determined considering the relative shear velocity between two particle groups within the influence domain and the friction of the interface.The proposed PTVD contact algorithm highlights the nonlocal characteristics of the SPH methods and avoids the complex algorithm for identifying and accurately describing the interface.Following the verification through the classic contact and friction examples,the PTVD algorithm is applied to the SPH analysis of quasi-static collapse of cohesionless granular soil and projectile penetration into soft soil.The results demonstrate the effectiveness and applicability of the proposed contact algorithm in SPH modelling of frictional contact problems.

smoothed particle hydrodynamics(SPH)methodfrictional contact interfacelarge deformationpoint-to-volume discrete(PTVD)contact algorithm

陈丁、黄文雄、黄丹

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河海大学力学与材料学院,江苏南京 211000

光滑粒子流体动力学法 摩擦接触界面 大变形 PTVD接触算法

国家自然科学基金国家自然科学基金江苏省卓越博士后计划

12302257117721172022ZB160

2024

岩土力学
中国科学院武汉岩土力学研究所

岩土力学

CSTPCD北大核心
影响因子:1.614
ISSN:1000-7598
年,卷(期):2024.45(3)
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