Numerical Investigation of Thin Plate Subjected to Blast Wave Propagation in Air and Water

Abstract

Numerical investigations on a thin rectangular plate subjected to air blast and underwater using LS DYNA is presented in this paper. For the analysis, the box model setup, air/water medium and target plate are modelled and the explosive is assumed at a distance of 150 mm from the target plate at the normal line passing through the centre of the plate. The target plate is modelled using piece-wise linear plasticity material model, the fluid using Gruinesian equation of state, air using linear polynomial equation of state and explosive using JWL equation of state. Parametric study in terms of charge weight is carried and the results are presented for various shock factors. The free field pressure time history and the permanent deformation are compared with experimental results available in literature. The study indicates that the permanent deformation is about 5.5 times that of air blast in underwater explosion.