Approximate methods for calculating the impact of a massive body on a plate lying on the base

Normal impact of a massive body on a uniformly stretched plate lying on the base is investigated. A hinged round or rectangular plate on an elastic base, or an infinite plate on the surface of an ideal incompressible fluid is considered. The solution to the elastoplastic impact is in good agreement with numerical calculations and experimental data. With a small parameter of elastic collapse, that is, with the developed local plastic deformations, a solution to the problem of impact with rigid-plastic local collapse can be used. Approximate formulas for calculating the main characteristics of rigid-plastic impact are set up.

Approximate Solution of the Varying Speed Impact of 3D Bodies on the Water Surface

The present paper proposes an approximate solution for the varying speed impact of 3D bodies on the water surface, with the assumptions that the fluid is considered to be incompressible, inviscid, weightless and with negligible surface tension effects and the flow ro be irrotational. The approximate solution provides a linear relationship between Cp and a dimensionless variable K, and the equation of body acceleration. These equations can be used to rapidly predict the pressure distribution on the body surface and the motions of the body. The predictions of the approximate solution match the CFD results very well for the varying speed impacts, including the normal and oblique impacts of a cone on the water surface and the normal impact of a pyramid on the water surface. The present approximate solution can be suitable for the 2D, axisymmetric and fully 3D impacts of bodies on the water surface with varying speed.

Ceramic Armour for Armoured Vehicles Against Large-Calibre Bullets

Modelling the armour-piercing bullets B-32 calibre 12.7 mm penetration into the double-layer ceramic-composite armour has been performed for the armour blocks of two designs. The first one is a layer of ceramic square tiles supported by the glass or polyamide fabric. Modelling and subsequent ballistic tests have shown that the conical Hertz crack localized in the ceramic tile is formed. The tile is destroyed from the spread of radial cracks, and the entire armour unit becomes unable to sustain the repeated hit of the bullet. In the second case, the armour block consists of the discrete epoxy-filled cylindrical ceramic elements with spherical ends. The advantage of this "discrete" armour is localization of the damage zone and thus an ability to sustain the multiple bullet hits. The ballistic tests of the compared armour units have shown that both provide effective additional protection of light-armoured vehicles against the normal impact of the calibre 12.7 mm bullet.