Evaluation of effectiveness of polymer coatings in reducing blast-induced deformation of steel plates

Incorporating elastomers such as polymers in protective structures to withstand high energetic dynamic loads, has gained significant interest. The main objective of this study is to investigate the influence of a Polyurea coating towards the blast-induced response in steel plates. As such, Polyurea coated steel plates were tested under near-field blast loads, produced by the detonation of 1 kg of spherical nitromethane charges, at a standoff distance of 150 mm. Mild steel (XLERPLATE 350) and high-strength steel (BIS80) plates with thicknesses of 10 mm were Polyurea coated with thicknesses of 6 mm and 12 mm on either the front (facing the charge) or the back face. The deformation profiles were measured using 3D scanning. Numerical simulations were performed using the non-linear finite element code LS-DYNA. The strain-dependent behaviour of the steel and Polyurea were represented by Johnson-cook and Money-Rivlin constitutive models, respectively. The numerical models were validated by comparing the plate deflection results obtained from the experiments and were then used in the subsequent parametric study to investigate the optimum thickness of the Polyurea coating. The results indicate that back face coating contributes towards an approximately 20% reduction in the residual deformation as well as the absence of melting of the Polyurea layer, while the front-face coating can be used a means of providing additional standoff distance to the steel plates.     

Becoming a disarmament champion: the Austrian crusade against nuclear weapons

ABSTRACT

The making of the Treaty on the Prohibition of Nuclear Weapons (TPNW) has put Austria and its involvement in nuclear disarmament in the spotlight. This study highlights several factors that led Austria to become a prominent voice in nuclear-disarmament debates. First, its involvement dovetails with the emphasis on humanitarian disarmament it has promoted since the 1990s. Second, a strong antinuclear identity pervades Austrian society. This “nuclear allergy” combines antimilitarism inherited from the Cold War and, more broadly, an aversion to nuclear power, including for energy purposes. These two considerations form the background to the increased activism of the Austrian Foreign Ministry on nuclear disarmament in international fora. But, equally, Austria’s crusade for the TPNW can be attributed to the engagement of a small team of diplomats implementing personal as well as national preferences in favor of disarmament.