Understanding the High Temperature & Fire Performance … · Understanding the High Temperature &...
Transcript of Understanding the High Temperature & Fire Performance … · Understanding the High Temperature &...
Understanding the High Temperature & Fire Performance of Composites
AP MouritzRoyal Melbourne Institute of Technology (RMIT University)
e-mail: [email protected]
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Research overview
• Understand high temperature & fire response of composites for diverse structural applications
• Understand following about composites in fire:
• thermal response
• damage & decomposition
• softening & failure
• residual mechanical properties
• Fire modelling & testing:
• Material level (fibre/ply/laminate)
• Structural level (component)
• Material systems:
• fibre-polymer laminates
• sandwich composites
• fibre metal laminates
Research vision
Towards a user-friendly generic modelling “toolbox” to predict thermal response, damage, burn-through & structural
integrity of composites during & following fire exposure.
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Research progress
• Models to predict temperature rise in laminates & sandwich composites exposed to fire.
• Models to predict decomposition & burn-through in laminates & sandwich composites exposed to fire.
• Models to predict softening & failure of laminates & sandwich composites exposed to fire.
• Models to predict post-fire mechanical properties of laminates & sandwich composites exposed to fire.
• Models to predict fire protection provided by passive and reaction coatings on laminates & sandwich composites exposed to fire.
Experimental validation
Experimental validation at different length scales has been central to our models
Fibre damage (<10 microns)
Microstructural damage (<1 mm)
Coupon testing (<0.5 mm)
Intermediate-scale testing (1 m)
Large-scale testing (3 m)
incre
asin
g e
xp
erim
en
tal s
cale
Thermal model
Fire reaction of polymer laminates & sandwich composites is a complex interactive problem
Hea
t F
lux
Fire-damaged
carbon/epoxy laminate
• Model developed to calculate temperature for any thermal flux condition of the fire.
• Model validated for composites tested at heat flux conditions from 10 kW/m2 (~250oC) to 100 kW/m2 (~800oC).
solid lines represent predictions
Thermal model
Hea
t F
lux
Decomposition model
Decomposition of laminates & sandwich composites to char is calculated using Arrhenius rate model.
0 2 4 6 8 10 120
20
40
60
80
100
Glass/polyester fabric
charmodel25.opj
Measured Char Thickness = 5.78 ± 1.23 mm
Rem
ain
ing R
esin
Conte
nt (%
)
Depth Beneath Hot Face (mm)
char virgin laminate
solid line represents predictions
He
at
Flu
x
0 2 4 6 8 10 120
2
4
6
8
10
12
charmodel27.opj
carbon/epoxy tape (50 kW/m2)
carbon/epoxy tape (75 kW/m2)
carbon/epoxy tape (100 kW/m2)
carbon/epoxy fabric (50 kW/m2)
glass/polyester fabric (25 kW/m2)
glass/polyester fabric (50 kW/m2)
glass/polyester fabric (75 kW/m2)
glass/polyester fabric (100 kW/m2)
glass/epoxy fabric (50 kW/m2)
glass/vinyl ester fabric (25 kW/m2)
glass/vinyl ester fabric (50 kW/m2)
glass/vinyl ester fabric (75 kW/m2)
glass/vinyl ester fabric (100 kW/m2)
glass/phenolic fabric (25 kW/m2)
glass/phenolic fabric (50 kW/m2)
glass/phenolic fabric (75 kW/m2)
glass/polyester mat (50 kW/m2)
glass/epoxy mat (50 kW/m2)
Measure
d C
har
Thic
kness (
mm
)
Theoretical Char Thickness (mm)
Accurate prediction of decomposition (char) for many composites under range of heat flux conditions.
Decomposition model
Compression model
Compressive
Load
Compressive
Load
Modelling based on the four step analysis:
1. Calculation of through-thickness temperature profile in composite
2. Calculation of temperature-dependent compression strength (matrix softening) at many points through the composite
3. Calculation of bulk strength of the composite
4. Prediction of compression failure.
Compression properties of polymer laminates & sandwich composites exposed to fire
He
at
Flu
x
Experimental validation of compression model using laminates & sandwich composites.
Compression model
0 300 600 900 1200 15000.0
0.2
0.4
0.6
0.8
1.0
75 kW/m2 (800
oC)
50 kW/m2 (600
oC)
25 kW/m2 (440
oC)
No
rma
lise
d C
om
pre
ssiv
e S
tre
ss
Time-to-failure (s)
glass/vinyl ester laminate
Model validation for polymer laminates & sandwich composites
failure time decreases with increasing applied stress & heat flux
plastic kinking failure
Compression model
Tension
Load
Tension
Load
Modelling based on the five step analysis:
1. Calculation of through-thickness temperature profile in composite
2. Calculation of temperature-dependent tension strength of polymer matrix at many points through the composite
3. Calculation of temperature-time dependent strength of fibres at many points through the composite
4. Calculation of bulk tensile strength of the composite
5. Prediction of tensile failure.
Tension properties of polymer laminates & sandwich composites exposed to fire
Tension model
Experimental validation of tension model.
Failure can occur after complete matrix decomposition.
solid lines represent predictions
Tension model
1 10 100 10000
50
100
150
200
250
Time (s)
Applie
d tensile
str
ess (
MP
a)
Tension
Load
Tension
Load
Outstanding research problems
• Past ten years characterised by major progress in fire modelling of composites.
• However, challenges remain.
– Mechanistic-based models for softening & oxidation of fibres at high temperatures.
– Model for predicting delamination cracking in hot, decomposing composites
– Model for various damage & failure modes of sandwich composites in fire
– Scaling laws
– Comparative studies with structural metals
– User-friendly modelling toolbox for composites in fire.
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• A.P. Mouritz, S. Feih, A. Afaghi Khatibi, B.Y. Lattimer and S.W. Case, United States Office of Naval Research Grant, ‘Fire
Modeling and Testing of Aluminum Alloys and Structures’, 2013-2016, N000141310590.
• A.P.Mouritz United States Office of Naval Research, International Workshop on Naval Structural Life Assessment Methodologies,
2011, N62909-11-1-7031.
• S. Feih, A.P. Mouritz, S.W. Case and A.P. Mouritz, United States Office of Naval Research, ‘Deformation modelling of naval
composite structures in Fire: Sensitivity Analysis and Optimization’, 2010, N00014-11-1-0223.
• S. Feih, A.P. Mouritz, S.W. Case and A.P. Mouritz, United States Office of Naval Research, ‘Fire Structural Properties of
Sandwich Composites’, 2010, N00014-12-1-0248.
• A.P. Mouritz, S. Feih, B.Y. Lattimer and S.W. Case, United States Office of Naval Research Grant, ‘Modeling of Aluminum Naval
Structures During and Following Fire’, 2010-2012, N00014-10-1-0690.
• A.P. Mouritz, United States Office of Naval Research Grant, ‘Development and Application of Fire Resistive Models for Naval
Composite Structures’, 2007-2009, N00014-07-0514.
• B. Lattimer and A.P. Mouritz, United States Office of Naval Research Grant, ‘Structural Integrity of Aluminum during Fires’, 2007-
2009, N00014-08-1-0300.
• A.P. Mouritz, United States Office of Naval Research Grant, ‘Structural properties of composites in fire’, 2003-2006.
• A.P. Mouritz, United States Office of Naval Research Grant, ‘Fire book’, 2002