Increasing Initial Internal Energy of Air Elements near Explosive for Fluid-Structure Models of a Steel Plate Subjected to Non-contact Explosion

This study was to simulate a steel plate subjected to non-contact explosion by using Arbitrary Lagrangian-Eulerian (ALE) algorithm of the LS-DYNA software. A 3-D Fluid-Structure interaction model was considered. The numerical result would be compared with S.D. Boyd’s experiment, which 250g Pentolite explosive detonated above a 5 mm thick steel plate. The Eulerian mesh for explosive and air and the Lagrangian mesh for steel plate and its supporting system were coupled together with overlap. The JWL equation of state and the linear polynomial equation of state were used for explosive and air respectively. A bilinear stress-strain relationship was assumed for the steel plate which was modeled with shell elements. By increasing initial internal energy of air elements near explosive with a temperature of 3000K, the maximum displacement of the midpoint of the steel plate from the ALE model for explosive with a standoff distance of 50 cm was improved from an error of -46.7% to 15.3% after compared with S. D. Boyd’s experiment in 2000. Besides, the maximum displacement for the case of explosive with a standoff distance of 25 cm can have an significant improvement with only 0.5% error.