SPH calculations of asteroid disruptions: The role of pressure dependent failure models
SPH calculations of asteroid disruptions: The role of pressure dependent failure models
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DOI：
10.1016/j.pss.2014.09.012
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发表时间：
2015-03-01
影响因子：
2.4
通讯作者：
Jutzi, Martin
中科院分区：
文献类型：
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作者：
Jutzi, Martin
我们提出了利用光滑粒子流体力学（SPH）技术对强度主导体的破坏建模的最新改进。改进包括更新强度模型和摩擦模型，并通过与室内实验的比较成功地进行了验证。在小行星灾难性破坏的建模中，新旧强度模型的比较表明，在最初无孔、完整且结构均匀的目标（如Benz和Asphaug， 1999年研究中使用的目标）的情况下，新旧强度模型没有明显偏差。然而，对于许多情况（例如，最初部分或完全损坏的目标和碎石桩结构），我们发现考虑摩擦和材料具有压力相关的抗剪强度是至关重要的。我们对灾难性破坏阈值（27，作为目标特性和目标尺寸的函数，可达100公里）的研究表明，在没有摩擦的情况下，完全损坏的目标具有Q(D)*:，这比包括摩擦的情况下显着（5-10倍）小。当考虑压实（孔隙破碎）能量耗散的影响时，靶材变得更强(Q(D)*；增加了2-3倍)。另一方面，内聚力在大尺度上的影响可以忽略不计，只有在小于或类似于1公里的尺度上才重要。我们的结果显示了强度、摩擦力和孔隙度对小型（小于或接近1000公里）物体碰撞结果的相对影响。这些结果将用于未来的研究，以改进现有的碰撞结果的比例定律（例如Leinhardt和Stewart， 2012）。(C) 2014 Elsevier Ltd.版权所有。
We present recent improvements of the modeling of the disruption of strength dominated bodies using the Smooth Particle Hydrodynamics (SPH) technique. The improvements include an updated strength model and a friction model, which are successfully tested by a comparison with laboratory experiments. In the modeling of catastrophic disruptions of asteroids, a comparison between old and new strength models shows no significant deviation in the case of targets which are initially non-porous, fully intact and have a homogeneous structure (such as the targets used in the study by Benz and Asphaug, 1999). However, for many cases (e.g. initially partly or fully damaged targets and rubble-pile structures) we find that it is crucial that friction is taken into account and the material has a pressure dependent shear strength. Our investigations of the catastrophic disruption threshold (27, as a function of target properties and target sizes up to a few 100 km show that a fully damaged target modeled without friction has a Q(D)*:, which is significantly (5-10 times) smaller than in the case where friction is included. When the effect of the energy dissipation due to compaction (pore crushing) is taken into account as well, the targets become even stronger (Q(D)*; is increased by a factor of 2-3). On the other hand, cohesion is found to have an negligible effect at large scales and is only important at scales less than or similar to 1 km.Our results show the relative effects of strength, friction and porosity on the outcome of collisions among small (less than or similar to 1000 km) bodies. These results will be used in a future study to improve existing scaling laws for the outcome of collisions (e.g. Leinhardt and Stewart, 2012). (C) 2014 Elsevier Ltd. All rights reserved.