Explosive Compaction of Solid Inert Three-Component Mixtures Taking into Account a Different Thickness of the Explosive Axial Layer

We consider the axisymmetric problem of explosive compaction of a mixture from aluminum, sulfur and carbon placed into a cylindrical steel ampoule. The inert substance (graphite) is added to the mixture to avoid the reaction between aluminum and sulfur. We found the essential influence of the thickness of the explosive layer on the final result of explosive compaction. Insufficient thickness of explosives, as well as the excessive thickness may be a reason for an incompletely compacted final product or lead to the formation of cracks or damage.

Numerical 3D-modeling of spall and shear fractures in shells of austenitic 12Kh18N10T steel and 30KhGSA steel under their spherical and quasi-spherical explosive loading

To pursue VNIIEF–VNIITF joint investigations, this paper briefly describes the experimental setup and provides numerical 3D-computation results (LEGAK-3D technique) on special features in the convergence dynamics of steel shells under their quasi-spherical explosive loading in the system with the 40-mm outer radius of the explosive layer. The computation results were compared with the data experimentally registered for shells of the 30KhGSA steel, both as-received and quenched to HRC 35…40, and the austenitic 12Kh18N10T stainless steel. The comparison was also made with laser-interferometry results obtained directly under explosive loading, as well as with gamma-tomography and scanning electron microscopy investigations of the recovered shells.

Experimental and Numerical Research in Explosive Loading of Two- and Three-Component Solid Mixtures

We have conducted experimental and numerical research in two- and three-component solid mixtures placed into a cylindrical recovery ampoule under explosive loading. Behavior of the mixture is described by a mathematical model of a multicomponent medium. In the model, every component of a mixture simultaneously occupies the same volume as the mixture. Components interact with each other, exchanging momentum, energy, and mass (if the chemical reaction between the components occurs). An equality of components’ pressure is chosen as a condition for joint deformation of components. Finite element method is used for solving the problems. We considered experimentally and numerically explosive loading of the<br />aluminum-sulfur mixture, and explosive compaction of the aluminum-sulfur-carbon mixture in a cylindrical steel ampoule. The inert substance (graphite) was added to the mixture to avoid the reaction between aluminum and sulfur. Most of the focus is on simulating the action of explosion products on the ampoule.<br />In the computations the actions of the detonation products surrounding the ampoule was simulated by the action of pressure on the upper part of the ampoule in a vertical (axial) direction and on the lateral surface of the ampoule in a horizontal (radial) direction. We varied the thickness of the explosive that acts on the upper part of the ampoule in the axial direction in order to study the influence of the parameter on a final shape and size of the ampoule. We founded the essential influence of the thickness of the explosive layer on the final result of explosive compaction. Insufficient thickness of explosives, as well as the excessive thickness may be a reason for an incompletely compacted final product or lead to the formation of cracks or damage.<br /><br />

Effectiveness of Explosive Reactive Armor

Explosive reactive armor (ERA) is a type of add-on armor that usually consists of tiles made of two metal plates with an explosive layer in between. The ERA is placed at a certain distance from the main armor to enhance its performance. ERA design is optimized based on the required effectiveness of the tiles. Various methods of defining ERA effectiveness are described. The effectiveness parameters of the mass-flux model and its derivatives, the effect of material properties, the escape length of the jet tip precursor, the explosive layer thickness, and the edge effects are analyzed, and correlations between them are presented. Analysis results are compared with available experimental data and a very good correlation is found.