SPH elastic dynamics
SPH elastic dynamics
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DOI：
10.1016/s0045-7825(01)00254-7
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发表时间：
2001-01-01
影响因子：
7.2
通讯作者：
Swift, RP
中科院分区：
文献类型：
--
作者：
Gray, JP;Monaghan, JJ;Swift, RP
流体动力学的标准平滑颗粒流体动力学（SPH）表现出一种称为拉伸不稳定性的不稳定性。这种不稳定可能在正压和负压时发生。通常，效果很小，但是在弹性或脆性固体的情况下，效果可能很严重。在张力下，脆弱的固体可能会断裂，但是由于拉伸不稳定，很难将物理断裂和碎片分裂与SPH颗粒的非物理结块。最近，我们中的一个（JJM）表明，如何通过人工压力来消除这种不稳定性，该压力引入了长波长模式中可忽略的错误。在本文中，我们展示了如何通过基于主要应力的符号来改善算法。我们从分散材料中弹性波的分散性关系中确定人造应力的参数。我们将算法应用于振荡束，碰撞环和脆性固体。结果与理论以及其他高准确的方法非常吻合。 （c）2001 Elsevier Science B.V.保留所有权利。
The standard smoothed particle hydrodynamics (SPH) formulation of fluid dynamics can exhibit an instability called the tensile instability. This instability may occur with both positive and negative pressure. Usually the effects are small, but in the case of elastic or brittle solids the effects may be severe. Under tension, a brittle solid can fracture, but it is difficult to disentangle the physical fracture and fragmentation from the nonphysical clumping of SPH particles due to the tensile instability. Recently, one of us (JJM) has shown how this instability can be removed by an artificial stress which introduces negligible errors in long-wavelength modes. In this paper we show how the algorithm can be improved by basing the artificial stress on the signs of the principal stresses. We determine the parameters of the artificial stress from the dispersion relation for elastic waves in a uniform material. We apply the algorithm to oscillating beams, colliding rings and brittle solids. The results are in very good agreement with theory, and with other high-accuracy methods. (C) 2001 Elsevier Science B.V. All rights reserved.