Numerical Simulation of Fluid-Structure Interaction and its Application in Impact of Low-Velocity Projectiles with Water Surface

In this article, finite element method and ALE formulation were used to numerically simulate impact of low-velocity specific projectiles with water surface. For the simulation, Ls-Dyna finite element code was used. Material models which were used to express behavior of air and water included Null material model. For the projectile, plastic-kinematics material model was applied. Mie-Gruneisen equation of state was also attributed to air and water. First, the results were validated by analyzing the impact of metallic cylinder with water surface and then impact of a mine as a low-velocity projectile was simulated. Among major outputs were force and pressure applied to the projectile, velocity and acceleration variations upon entering water, stress-strain variations and variations of water surface in various steps of analysis. The results showed that impact of structure with fluid can be modeled using finite element model with high accuracy in terms of quality and quantity.