EXPLOSION CAMERAS WITH PROTECTIVE FOAMY LINING: DEFORMATION MODES ARISING UPON EXPLOSIVE LOADING EPNM-2012, Strasburg A. G. Kazantsev 2, S. S. Smolyanin 2, L. B. Pervukhin 1, P. A. Nikolaenko 1, and R. D. Kapustin 1 1 Institute of Structural Macrokinetics and Materials Science RAS, Chernogolovka, Moscow, Russia 2 Central Research Institute for Machinery Industry (TsNIITMash), Moscow, Russia

As is known, from the published data, gas-liquid foams most effectively use for effective dissipation of shock energy. But gas-liquid foams exhibit a restricted service life. In this work, we explored the applicability of solid refractory foams for the above purpose.

Purpose of the work - to determine the effectiveness of the dissipation of explosive energy by solid porous materials (solid foams). In the represented work is investigated the possibility of application for the dissipation of the shock waves of the solid aluminosilicate porous materials VBF of the production Privately held company NPKF “MaVR”. Purpose of the work

Experimental model finite-element model Metall shell Cellular material VBF explosive charge (TNT); air

Strains in metall shell TNT m=600 gramm Model without solid aluminosilicate porous material VBF TNT m=900 gramm Model with solid aluminosilicate porous material VBF

Pressure upon a container wall TNT m=600 gramm Model without solid aluminosilicate porous material VBF TNT m=900 gramm Model with solid aluminosilicate porous material VBF

Plastic deformations in metall shell A) TNT m=600 gramm Model without solid aluminosilicate porous material VBF В) TNT m=900 gramm Model with solid aluminosilicate porous material VBF

Experimental model 1 – Cellular material VBF ; 2 – the strain gauge; 3 – explosive charge (TNT); 4 – the electric detonator; 5 – camera for the electric detonator and opening for wires or detonation cord; 6 – metall shell of the experimental model;

Strains in metall shell of experimental models, MPa TNT mass, gramm Model without solid aluminosilicate porous material VBF Model with solid aluminosilicate porous material VBF the upper surfaceThe sidethe upper surfaceThe side 20072,28831,842, ,72431, ,3397,2137,8194, ,9423,4

The calculation of the efficiency of shock energy dissipation Q V = 1,4/0,14 = 10 MJ/m3 = 10 J/sm3 Q V – volumetric energy-absorption of material VBF; Q П – the quantity of energy, absorbed by material VBF according to the results of the tests of experimental models; V – the volume of material VBF in the experimental models

Calculation of the stress-strain state Material of metall shell – steel 9MnSi5; Diameter-1,2 m, Thickness of a wall-12 mm Mass without VBF 700±20 kg Cellular material VBF, thickness of a layer of 300 mm ρ = 0,7 gramm/sm3 При R≤αr 0 TNT, kgr, mσ н, МПа 0,250, ,50, ,750, , ,250, ,50, ,750, , ,250, ,50, ,750, , ,250, ,50,08762 где: σ н – Strains in metall shell caused by influence on it of a shock wave, R об – radius of metall shell, δ – thickness of metall shell, r 0 –TNT radius, α = 10 – the factor considering limiting expansion of products of a detonation, Q – specific energy allocation of TNT, Е – material,s elasticity module of shell, ρ 0 – TNT density, ρ в – air density, μ – Poisson's ratio

The results of the experiment m TNT,kgL sircle, mm of metall shell before explosion L sircle, mm of metall shell after explosion relative lengthening Notes 3, ,5Plastic deformation is negligible or no 4, ,3Plastic deformation 7, ,2tensile strength exceeding

Main conclusions 1) Is developed the procedure of the experimental determination of the energy-dissipate ability of the solid cellular materials by the method of their accomodation into closed metal shell from a change in the deformation of this of shell. 2) Used the method of calculation, based on the method of finite elements and the combined Lagrangian-Eulerian formulation of the equations of motion of a continuous medium. It allows to adequately describe the impact of a shock wave on the wall of the pilot sample, as with VBF, so without it. Experimental results were found to reasonably agree with calculated ones. 3) The foamy materials under investigation showed good results: the efficiency of shock energy dissipation was found to attain a value of about 10 J/cm3. Material VBF with the volume of 1 m3 absorbs the energy, isolated with explosion of the charge of TNT by the mass of 2,4 kg. 4) The scale factor in the case of a proportional increase in sample sizes and thickness of energy absorbing layer does not affect the ability of the VBF dissipation of shock energy

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