Computational Simulation Computational Simulation of Blast Effects on of Blast Effects on Structural Components Structural Components Daniel G. Linzell Daniel G. Linzell Associate Professor Associate Professor Civil and Environmental Engineering Civil and Environmental Engineering Lyle N. Long Lyle N. Long Distinguished Professor Distinguished Professor Aerospace Engineering Aerospace Engineering Abner Chen Abner Chen Ph.D. Candidate Ph.D. Candidate Civil and Environmental Engineering Civil and Environmental Engineering Emre Emre Alpman Alpman Postdoctoral Researcher Postdoctoral Researcher Aerospace Engineering Aerospace Engineering
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Computational Simulation Computational Simulation of Blast Effects on of Blast Effects on Structural ComponentsStructural Components
Daniel G. LinzellDaniel G. LinzellAssociate ProfessorAssociate ProfessorCivil and Environmental EngineeringCivil and Environmental Engineering
Lyle N. LongLyle N. LongDistinguished ProfessorDistinguished ProfessorAerospace EngineeringAerospace Engineering
Abner ChenAbner ChenPh.D. CandidatePh.D. CandidateCivil and Environmental EngineeringCivil and Environmental Engineering
Detailed coupled gas/chemistry simulations of detonations Large scale simulations of pressure loadings using time-accurate CFDFluid/structure simulations under blast/impact loadingsCoating materials to help make structures blast/impact resistant – polyurea
Background – Blast resistant materials (polyurea)
PolyureaIntroduced by Texaco in 1989Known Advantages vs. Polyurethanes (traditional coatings)Applications
Other – Civil InfrastructureRail carsWater storage tanksChemical plant infrastructure
Sources: PCI: http://www.pcimag.com/CDA/Archives/779f754db76a7010VgnVCM100000f932a8c0DefenseReview.com: http://www.defensereview.com/article502.html, Polymer Materials for Structural Retrofit, Knox et al., AFRL
DoDapplications –Polyurea
AFRLERDC-WESArmyNavyPentagon
RetrofitPublic domain?
Source: Polymer Materials for Structural Retrofit, Knox et al., AFRL; Army Times
Untreated stud wall
Coated with polyurea
Background – Blast resistant materials (polyurea)
Blast Simulation CFD Method
Unstructured-grid, time-accurate Euler codeFinite volume, Runge-Kutta time marchingCode is called PUMA2Has been in use at Penn State for many years, thoroughly validated on a wide range of problems
Blast CFD - Assumptions
75 lbs. of TNTExplosive is spherical in geometryUniform explosion
Blast CFD - Initial Pressure Profile
Initial Pressure Profile
0
20000
40000
60000
80000
100000
120000
140000
160000
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
r/R
p/p
0
Blast CFD - Pressure HistoryPressure Histories at Different Locations
Mechanisms behind protection?Mechanisms behind protection?Parameters to control performance?Parameters to control performance?
Background –Fluid/structure simulations
3-D
Focus Areas –fluid/structure interaction
Numerical fluid/structure programMaterial modelsComparison of ABAQUS and LS-DYNAComparison of PUMA2 and ConWepEffect of polyurea on steel plate under blast loading
Numerical fluid/structure programMaterial models – via literatureComparison of ABAQUS and LS-DYNAComparison of PUMA2 and ConWepEffect of polyurea on steel plate under blast loading
Johnson-Cook material model (Kurtaran and Eskandarian, 2003)A=66.7, B=100.4, n=0.26, C=0.014, and m=1.03
( )[ ] ( )[ ][ ]m**npl T1εCln1εBAσ −++= &
plε : equivalent plastic strain
*ε& : normalized plastic strain rate
roommelt
room
TTTT
T−−
=*
Material model - PolyureaPolyurea (APCI)
Mie-Gruneisen equation of state (Fuentes 2006)A hydrodynamic material modelA function of density and internal energy
)( HmH EEPP −Γ=− ρ
ρρ0
0Γ=Γ 0Γ 0ρ
02ρηH
HPE =
ρρ
η 01−=
2
200
)1( ηηρ
sC
PH −= C0 and s are material constants
: material constant : reference density
Numerical programAbaqus - ExplicitLS-DynaPUMA2
Fluid/structure interaction
Numerical fluid/structure programMaterial modelsComparison of ABAQUS and LS-DYNAComparison of PUMA2 and ConWepEffect of polyurea on steel plate under blast loading
)Comparison of internal energy for mesh size 1"x1"x1"
LS-DYNAABAQUS
Fluid/structure interaction
Numerical fluid/structure programMaterial modelsComparison of ABAQUS and LS-DYNAComparison of PUMA2 and ConWepEffect of polyurea on steel plate under blast loading
Blast function (ConWep)U.S. Army Waterways Experiment StationEmpirical model
Configuration of the model
Comparison of displacements
0 0.002 0.004 0.006 0.008Time (s)
-12
-10
-8
-6
-4
-2
0z-
disp
lace
men
t (in
)
PUMA2ConWep
Comparison of von Misesstress
0 0.002 0.004 0.006 0.008Time (s)
0
20000
40000
60000
80000
100000
120000
140000
160000
180000V
-M s
tress
(psi
)
PUMA2ConWep
Fluid/structure interaction
Numerical fluid/structure programMaterial modelsComparison of ABAQUS and LS-DYNAComparison of PUMA2 and ConWepEffect of polyurea on steel plate under blast loading
Numerical fluid/structure programMaterial modelsComparison of ABAQUS and LS-DYNAComparison of PUMA2 and ConWepEffect of polyurea on steel plate under blast loading