Simulation and test for whipping response of ship-like structure subjected to underwater explosion

Abstract

This study aims to verify the whipping phenomenon through an underwater explosion (UNDEX) experiment. Futhermore, comparison of the simulation and experimental results is conducted. The simulation is conducted using a coupling code that is a combination USA code and LS-Dyna. An actual whipping test is conducted at a reservoir. To study the whipping response due to an underwater explosion, an 8.4 m (L) × 0.68 m (B) ship-like structure is constructed using aluminum. Blast pressure sensors, velocity meters, accelerometers, and strain gauges are used for measuring the whipping response induced in the structure by the UNDEX.For the simulation, a finite element model of the structure is created using VPG™ and a 2nd order doubly asymptotic approximations (DAA2) boundary was used for solving the FSI. Furthermore, the 2nd generation Geers-Hunter bubble model was used for conducting the simulations. The velocity, acceleration, and stress obtained through the simulation and experiment were compared.In addition, a near-field explosion simulation and experiment were performed in this study. The simulation was carried out using the arbitrary Lagrangian-Eulerian (ALE) method by LS-Dyna. The deformation of the structures as determined through the simulation and experiment was compared.