Abstract Lagrangian particles in the material point method (MPM) are free to flow through the background Eulerian mesh to represent material deformation. Excessive compression or tension in the kinematic field tends to entangle the particles from the initial uniform configuration, causing artificial voids or aggregations that lead to loss of the continuity of the stress field and the singular deformation gradient of the particles, undermining computational robustness and accuracy. In this paper, the reseeding operation is performed in elements depending on the numbers of the accommodated particles and their accumulated deformations. The state variables of the reseeded particles are recovered from their surrounding old counterparts. The stresses of the reseeded particles around the structure are adjusted to mitigate the fluctuations of contact force from errors in the state recovery. Benchmark problems of deep penetration of a wished-in-place T-bar and the dynamic impact of a submarine landslide on a partially buried mudmat are analysed. The results of the MPM analyses are validated by comparison with the exact solutions by theoretical analyses and the numerical predictions using computational fluid dynamics (CFD) simulations.

中文翻译：

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在土-结构相互作用的物质点法中重新播种颗粒

摘要 材料点法（MPM）中的拉格朗日粒子可以自由流过背景欧拉网格来表示材料变形。运动场中的过度压缩或拉伸往往会使粒子从初始均匀配置中缠结，导致人工空隙或聚集，从而导致应力场的连续性和粒子的奇异变形梯度丧失，从而破坏计算的稳健性和准确性。在本文中，根据容纳粒子的数量及其累积变形，在单元中执行重新播种操作。重新播种的粒子的状态变量从它们周围的旧对应物中恢复。调整结构周围重新播种粒子的应力，以减轻由于状态恢复错误而导致的接触力波动。分析了预期的 T 型杆深度穿透的基准问题以及海底滑坡对部分掩埋泥垫的动力影响。通过与理论分析的精确解和使用计算流体动力学 (CFD) 模拟的数值预测进行比较，对 MPM 分析的结果进行了验证。