the blast load response of honeycomb sandwich panels y. chi supervisors: prof g. n. nurick, dr g. s....
TRANSCRIPT
TThe Blast Load he Blast Load Response of Response of Honeycomb Sandwich Honeycomb Sandwich PanelsPanels
TThe Blast Load he Blast Load Response of Response of Honeycomb Sandwich Honeycomb Sandwich PanelsPanelsY. ChiY. Chi
Supervisors: Prof G. N. Nurick, Dr G. S. LangdonSupervisors: Prof G. N. Nurick, Dr G. S. Langdon
Blast Impact Survivability Research Unit (BISRU),Blast Impact Survivability Research Unit (BISRU),
University of Cape TownUniversity of Cape Town
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BackgroundBackground
• Passenger Aircraft SafetyLockerbie Plane Crash
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General Aim
In search of better In search of better protection against protection against blastblast
In search of better In search of better protection against protection against blastblast
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Specific Aims of This Study
• To determine the response of honeycomb sandwich panels to uniformly distributed air-blast loading.
• To investigate the effect of:• Core thickness
• Plate thickness
• Core material
• Core configuration
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Structure Under Investigation
Front face plate
Back face plate
Aluminium honeycomb core
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Presentation Structure
• Blast test configurationsVarious panel configurations have been proposed and tested
• Quasi-static testing on the componentsCharacterise the materials(mild steel plates and aluminium honeycombs)
• Blast testing on the sandwich panels
• Concluding remarks
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Experimental Setup
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Panel Configurations
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Dharmasena et al, 2007, in press
Background Knowledge
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Background Knowledge
Dharmasena et al, 2007, in press
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Honeycomb Material Characterisation
Jones, Structural impact
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Honeycomb Material Characterisation
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Background Knowledge
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Focus of Today
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Single-1.6: 1.6mm plate 29mm h/c
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Single-1.6: 1.6mm plate 29mm h/cFront plate deflection – 5.3Ns to 29.2Ns
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Mid-point deflection of the face plates and the honeycomb cores
Single-1.6: 1.6mm plate 29mm h/c
0
5
10
15
20
25
30
0 5 10 15 20 25 30 35 40 45 50
Impulse (Ns)
De
fle
cti
on
(m
m)
Single-1.6 Front Single-1.6 BackH/c Front surface H/c Back surfaceLinear (Single-1.6 Front) Linear (Single-1.6 Back)
Trendline of plate deflection Honeycomb
deflection
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Single-1.6: 1.6mm plate 29mm h/c
at the center
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Honeycomb Material Characterisation
Densification
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0
5
10
15
20
25
30
0 5 10 15 20 25 30 35 40 45 50
Impulse (Ns)
Cru
sh d
ista
nce
(m
m)
Honeycomb crush distance graph
Densification = 29.2Ns
Single-1.6: 1.6mm plate 29mm h/c
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Single-1.6: 1.6mm plate 29mm h/c
Back plate deflection – 5.3Ns to 36.8Ns
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11g
1.6mm
11g
1.0mm
Effect of Plate Thickness
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1.6mm vs 1.0mm Plate Thickness
0
5
10
15
20
25
30
0 5 10 15 20 25 30 35 40 45 50
Impulse (Ns)
De
fle
cti
on
(m
m)
Single-1.6 Front Single-1.6 BackSingle-1.0 Front Single-1.0 BackLinear (Single-1.6 Front) Linear (Single-1.6 Back)Linear (Single-1.0 Front) Linear (Single-1.0 Back)
Mid-point deflection of the face plates
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1.6mm vs 1.0mm Plate Thickness
Honeycomb crush distance graph
0
5
10
15
20
25
30
0 5 10 15 20 25 30 35 40 45 50
Impulse (Ns)
Cru
sh d
ista
nce
(m
m)
Single-1.0 Single-1.6 Linear (Single-1.0) Linear (Single-1.6)
Densification
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Mid-point deflection of the face plates
1.6mm vs 1.0mm Plate Thickness
0
5
10
15
20
25
30
0 5 10 15 20 25 30 35 40 45 50
Impulse (Ns)
De
fle
cti
on
(m
m)
Single-1.6 Front Single-1.6 BackSingle-1.0 Front Single-1.0 BackLinear (Single-1.6 Front) Linear (Single-1.6 Back)Linear (Single-1.0 Front) Linear (Single-1.0 Back)
Densification Densification
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• For the effect of plate thickness:
A honeycomb sandwich panel with thinner face plates will have
higher front face plate deformation. This means the core will
densify at a lower impulse and transmit larger forces to the back
plate. This is generally undesirable.
• This, in conjunction with the effect of the core thickness, provides a detailed investigation of the response of honeycomb sandwich panels to blast loading.
• Further details will be available in my MSc thesis.
Concluding Remarks