The response of a structure subjected to the impact of a dry sand slug has been studied using a fully coupled approach, in which a novel algorithm based on the smoothed particle hydrodynamics (SPH) method is proposed for soil-solid interaction (SSI). The proposed algorithm is a hybrid continuum/discrete approach that can determine two regimes of contact behavior. When the granular assembly has a high relative velocity in dealing with the structure, initially, the short-term particle-to-particle contacts take place, resembling molecular collisions in a fluid and referred to as regime I. Then, the increase of the relative density of aggregate particles leads to semi-permanent contacts, referred to as regime II. The present aim is development of a coupling model that includes both regimes. The simulation of impact of granular slug into a rigid or deformable target leads to large numerical errors and even divergences. To overcome the limitation of traditional SPH approach that the density estimate is a major challenge in high-rate deformation problems, the number-density scheme is extended to the fully compressible approach. Finally, the proposed SSI Algorithm is validated with Liu et al.’s results [1] to simulate the interaction of a structure with sand slugs traveling at high velocities.

利用完全耦合的方法研究了结构在干砂弹作用下的响应，其中提出了一种基于光滑粒子流体动力学（SPH）方法的新算法，用于土固相互作用。所提出的算法是一种混合连续/离散方法，可以确定两种接触行为方式。当粒状组件在处理结构时具有较高的相对速度时，最初，会发生短期的粒子间接触，类似于流体中的分子碰撞，称为状态I。然后，相对粒子数增加聚集体颗粒的密度导致半永久性接触，称为II型。当前的目的是开发一种包括两种方案的耦合模型。模拟粒状块料对刚性或可变形目标的撞击会导致较大的数值误差甚至发散。为了克服传统SPH方法的局限性，即密度估计是高速变形问题中的主要挑战，数密度方案扩展到了完全可压缩的方法。最后，所提出的SSI算法已经用Liu等人的结果[1]进行了验证，以模拟结构与高速运动的砂的相互作用。