Transcript Вавилон

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. Kapustin1
1
Institute of Structural Macrokinetics and Materials Science
RAS, Chernogolovka, Moscow, 142432 Russia
2 Central Research Institute for Machinery Industry
(TsNIITMash), Moscow, Russia
[email protected]
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
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”.
Experimental model
Metall shell
Cellular material
VBF
explosive charge
(TNT);
air
finite-element model
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;
Dependence of the strains in metall shell of experimental
models from the mass of explosive charge (TNT)
1600
1400
1200
σ,МПа
1000
расчёт верх
расчёт бок
800
пустой верх
600
пустой бок
400
материал ВБФ-650 бок
материал ВБФ-650 верх
200
0
0
200
400
600
800
1000
1200
TNT mass, gramm
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 surface
The side
the upper surface
The side
200
72,2
88
31,8
42,6
400
244
304,7
24
31,8
600
352,3
397,2
137,8
194,1
341,9
423,4
900
The calculation of the efficiency of shock
energy dissipation
QП
QV 
V
QV = 1,4/0,14 = 10 MJ/m3 = 10 J/sm3
QV – volumetric energy-absorption of material VBF;
QП – 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
н 
0,28 0
R 2
  R 3  
r33r03QE 1    1 в 
  r3   0  При R≤αr0
1   
где: σн – Strains in metall shell caused by influence
on it of a shock wave, Rоб – radius of metall shell, δ –
thickness of metall shell, r0 –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, ρ0 – TNT
density, ρв – air density, μ – Poisson's ratio
TNT, kg
r, m
σн, МПа
0,25
0,033
110
0,5
0,042
168
0,75
0,048
220
1
0,053
271
1,25
0,057
321
1,5
0,06
371
1,75
0,064
420
2
0,066
469
2,25
0,069
518
2,5
0,072
567
2,75
0,074
616
3
0,076
665
3,25
0,078
713
3,5
0,08
762
The results of the experiment
mTNT,kg
Lsircle , mm
Lsircle , mm
of metall
of metall shell
shell before
after
explosion
explosion
relative
lengthening
Notes
3,5
3852
3871
0,5
Plastic deformation
negligible or no
is
4,5
3852
3902
1,3
Plastic deformation
7,0
3832
4030
5,2
tensile 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


THANK YOU FOR
ATTENTION!