Fire Modelling and Transfer of Heat
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Transcript of Fire Modelling and Transfer of Heat
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8/18/2019 Fire Modelling and Transfer of Heat
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9-2. Fire behaviour
František Wald
Czech Technical Universit in Pra ue
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Objectives
Repetition Nominal fire
curves
Parametric fire
• Models of fire
• Software supports
u v
Advanced fire
models
• Models of transfer of heat into structure Assessment 1
Thermal response
• o ware suppor s• Example of test on building
Unprotected steel
Protected steel
Software support
Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 092
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Objectives
Repetition
Nominal fire
curves
Parametric fire
u v
Advanced fire
modelsDesign of building
Design of building
Assessment 1
Thermal responseFire safety requirements
National fire regulations
Fire safety requirements
National fire regulations
Unprotected steel
Protected steel
Software support
Advanced modelsFire test of elements Parametric curves Nominal curves
. .
Calcul . of structure temp.
Assessment 2
Fire tests
in Cardington
Fire safety
Struct. analyses
Step by step procedure Fire testsFinite element
based on elements
Conclusions
Notes
Fire safety of structure
rucura eemenoe s ruc ure ar o e s ruc ure
Lecture 9-1, V001, April 093
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Objectives
Repetition
Nominal fire
curves
Parametric fire
EurocodesFire design
u v
Advanced fire
models
Fire behaviour
EN 1991-1-2Modelling of the gas temparature
Assessment 1
Thermal response
in the fire compartmentUnprotected steel
Protected steel
Software support
EN 1991-1-x
Transfer of heatand development in structure
Assessment 2
Fire tests
in Cardington
Mechanical load
x- -
Structural response
Conclusions
Notes
Lecture 9-1, V001, April 094
Design of structure at elevated temparature
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Objectives
Repetition Nominal fire
curves
Parametric fire
Parametric curves
u v
Advanced fire
models
Zone models
Assessment 1
Thermal response
CFDComputational Fluid Dynamics
Unprotected steel
Protected steel
Software support
Assessment 2Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 09
ruc ura response
5
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Objectives
Repetition
Nominal firecurvesParametric fire
Temperature, °C
Pre- flashover Post- flashover
°
u v
Advanced fire
models
-
Flashover
Assessment 1
Thermal response
Unprotected steel
Protected steel
Software support
Nominal standard
fire curve
Temperature
during fire
Assessment 2
Fire tests
in Cardington
Time, min
Conclusions
Notes
Lecture 9-1, V001, April 096
Cooling ….gn on ea ng
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Objectives
Repetition Nominal fire
curves
Parametric fire
( )18log34520 10g ++=
t θ
u v
Advanced fire
models
Nominal external curve
t t 38,032,0 −− −−=
Assessment 1
Thermal response
Nominal hydrocarbon curve
g ,,Unprotected steelProtected steel
Software support
( )t t 5,2167,0g e675,0e325,01108020 −− −−+=θ Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 09 7
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Objectives
Repetition
•
Nominal fire
curves
Parametric fire
u v
Advanced fire
models
Nominal h drocarbon curve1200
Gas temparature, °C
Assessment 1
Thermal response
1000
Unprotected steel
Protected steel
Software support
Nominal standard fire curve800
Assessment 2
Fire tests
in Cardington
400Conclusions
Notes200
Lecture 9-1, V001, April 098
0 15 30 45 60 90 120 150 180
,0
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Objectives
Repetition Nominal fire
curves
Parametric fire
• Has limitations
– Not based on real fire data
u v
Advanced fire
models
– Test repeatability difficult
– No cooling phase
Assessment 1
Thermal response
– Uniform heating
– Uses as tem erature “not fair”
Unprotected steel
Protected steel
Software support
• But Assessment 2
Fire tests
in Cardington –
– Can be useful for crudely comparing products
Conclusions
Notes
Lecture 9-1, V001, April 099
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Objectives
Repetition Nominal fire
curves
Parametric f ire
Parametric curves
u v
Advanced fire
models
Zone models
Assessment 1
Thermal response
CFDComputational Fluid Dynamics
Unprotected steel
Protected steel
Software support
Assessment 2Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 09
ruc ura response
10
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Objectives
Repetition Nominal fire
curves
Parametric f ire
• No heat built-up in pre-flashover phase of fire
• Temperature uniform in the compartment
u v
Advanced fire
models
• Uniform heat transfer coefficient in compartment
boundaries
Assessment 1
Thermal response
• com us on a es p ace n e compar menUnprotected steel
Protected steel
Software support
Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 0912
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Objectives
Repetition Nominal fire
curves
Parametric f ire
The calculation is in Annex A of EN 1991-1-2
• The size of the compartment is limited to 500 m2
u v
Advanced fire
models
• The openings are in the walls only(no openings in the roof)
Assessment 1
Thermal response
• The fire load density qt,d from 50 to 1000 MJ/m2
(about 3,5 kg to 70 kg of timber / m2)
Unprotected steel
Protected steel
Software support
• Cellulosic type of fire load1000
Gas temperature, °C
Assessment 2
Fire tests
in Cardington
400
600
Heating Cooling
Conclusions
Notes
Lecture 9-1, V001, April 09
0 0 15 30 45 60 90 120 Time, min
13
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Objectives
Repetition
In ut data
Nominal fire
curves
Parametric f ire
Fire load density qt,d for calculation of t tmax
u v
Advanced fire
models
Geometry of the fire compartment[ ]21 /
t
v m A
h AO =
Assessment 1
Thermal response
Thermal properties of boundary of enclosure[ ]K smJ c b / 212λ ρ =
Unprotected steel
Protected steel
Software support
Time modification factor
2
⎟⎟
⎠
⎞⎜⎜
⎝
⎛
= ref O
O Assessment 2
Fire tests
in Cardington
⎟⎟ ⎠
⎞⎜⎜⎝
⎛
ref b
bConclusions
Notes
Lecture 9-1, V001, April 09
c ve me n ours t t Γ =
14
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Objectives
Repetition
Two arts of the arametric fire curve
Nominal fire
curves
Parametric f ire
The curve in the burning phase
***
u v
Advanced fire
models
,,tg, e,e,e,
−−− −−−+= Assessment 1
Thermal response
The curve in the cooling phase (depends on t *
max , e.g.)
x t t *max*
maxtg, 250 −−= θ θ
Unprotected steel
Protected steel
Software support
600
800
1000Gas temperature, °C Assessment 2
Fire tests
in Cardington
0
200
400
0 15 30 45 60 90 120 Time, min
Heating CoolingConclusions
Notes
Lecture 9-1, V001, April 09 15
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Objectives
Repetition
•
Nominal firecurves
Parametric f ire
– t max = 0,2 10-3 q
t,d
/ O
u v
Advanced fire
models
– max = max
Assessment 1
Thermal response
• Fire driven by fire load – t max = t lim = 25 min (fast fire or 20 min and 15 min slow fire)
Unprotected steel
Protected steel
Software support
– t* max = t max Γ lim800
1000Gas temperature, °C Assessment 2
Fire tests
in Cardington
200
400
600
Heating Cooling
Conclusions
Notes
Lecture 9-1, V001, April 0916
0
0 15 30 45 60 90 120 Time, min
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Objectives
Repetition Nominal fire
curves
Parametric f ire
Av
u v
Advanced fire
models
[ ]21t
v / m A
O = Af
H hb
Assessment 1
Thermal response
Av area of openingh height of opening
Unprotected steel
Protected steel
Software support
At total surface area of the enclosure(walls, ceiling and floor, including the openings)
Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 09 17
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Objectives
Repetition Nominal fire
curves
Parametric f ire
• Small openings - longer and colder fires
• Large openings - faster and hotter fires
u v
Advanced fire
models
1200
Temperature, °C)
Assessment 1
Thermal response
800
1000
Unprotected steel
Protected steel
Software support
400
600
0,02
1/2
0,02
factor O [m ]
Small openings
Opening Assessment 2
Fire tests
in Cardington
200
,
0,1
0,15
0,2
,
0,1
0,15
0,2 Large openings
Conclusions
Notes
Lecture 9-1, V001, April 0918
0 15 30 60 Time, min45
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Objectives
Repetition Nominal fire
curves
Parametric f ire
• Low fire load - shorter and coulder fires
• High fire load - longer and wormer fires
u v
Advanced fire
models
1000
θ
Fire load density [MJ/m ]22
Temperature, °C
Assessment 1
Thermal response
800
200
400
600
Unprotected steel
Protected steel
Software support
400
6001000
Assessment 2
Fire tests
in Cardington
200
Conclusions
Notes
Lecture 9-1, V001, April 0919
0
0 60 1200 15 30 60 90 120 Time, min45
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Objectives
Repetition Nominal fire
curves
Parametric f ire
- – .
• Isolated walls – lower cooling - higher temp.
u v
Advanced fire
models
Temperature, °C
b = 702
[ ]K sJ/m λc ρb / 212=
Assessment 1
Thermal response
800
1000
b = 2000
Unprotected steel
Protected steel
Software support
600 Gypsum board
Light weight concreteb = 1120
Assessment 2
Fire tests
in Cardington
200
Normal concrete
Nominal standard fire curve
For fire load qf d = 700 MJ/m2
Conclusions
Notes
Lecture 9-1, V001, April 0920
00 30 60 90 120 Time, min
,
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Objectives
Repetition Nominal fire
curves
Parametric fire
• More sophisticated energy balance models
• Assume uniform temperatures in each zone
u v
Advanced fire
models
• Normally computer based
Assessment 1
Thermal response
• evera commerc a co es ava a e eg.
Ozone, CFast
Unprotected steel
Protected steel
Software support
• Similar drawbacks and benefits to parametric
curves
Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 0921
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Objectives
Repetition Nominal fire
curves
Parametric fire
Parametric curves
u v
Advanced fire
models
Zone models
Assessment 1
Thermal response
CFDComputational Fluid Dynamics
Unprotected steel
Protected steel
Software support
Assessment 2Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 09
ruc ura response
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Objectives
Repetition Nominal fire
curves
Parametric fire
• Based on partial differential equations:
–Mass balance
u v
Advanced fire
models
• the air (oxygen) entering the fire compartment is used for burning of the
fuel, the amount of the incoming air and the gases created as result of
the burning is equal to the amount of gas escaping through the openings
Assessment 1
Thermal response
–Energy balance• the energy released from the burning is used to heat the gas in the fire
Unprotected steel
Protected steel
Software support
compartment, the walls, floor and ceiling, some energy is „lost“ as the
gas exits the compartment through the openings
Assessment 2
Fire tests
in Cardington
Two zone model
Conclusions
Notes
Lecture 9-1, V001, April 09
One zone model
23
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Objectives
Repetition Nominal fire
curves
Parametric fire
Parametric curves
u v
Advanced fire
models
Zone models
Assessment 1
Thermal response
CFDComputational Fluid Dynamics
Unprotected steel
Protected steel
Software support
Assessment 2Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 09
ruc ura response
24
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Objectives
Repetition Nominal fire
curves
Parametric fire
• Computational Fluid Dynamics
• Can predict huge range of phenomena
u v
Advanced fire
models
• Difficult to use
due to man uncertainties in in ut variables
Assessment 1
Thermal response
• Still more a research method
Unprotected steel
Protected steel
Software support
xamp e o s mu a onthe influence of the ceiling surface on the temperature development during the
seventh Cardington large fire test
Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 0925
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Objectives
Repetition Nominal fire
curves
Parametric fire
• The simple tools are developped for
– Parametric fire curves
u v
Advanced fire
models
• eg. DIFISEK-EN 1991-1-2 Annex A
–
Assessment 1
Thermal response
• eg. Ozone programme
Unprotected steel
Protected steel
Software support
•
summarised in Assessment 2
Fire tests
in Cardington
• a a aseConclusions
Notes
Lecture 9-1, V001, April 0926
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Objectives
Repetition Nominal fire
curves
Parametric fire
• Are there some advantages of nominal fire curves?
• What are the advantages of parametric fire curves?
u v
Advanced fire
models
• What determine the maximal temperature of the parametric
fire curve?
Assessment 1
Thermal response
• ow s s mu a e coo ng y parame r c re curve
• Describe the principles of zone models?
Unprotected steel
Protected steel
Software support
Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 0927
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Objectives
Repetition Nominal fire
curves
Parametric fire
u v
Advanced fire
models
Fire behaviour (based on Standard fire curve) Assessment 1
Thermal response
Simple heattransfer models
Unprotected steel
Protected steel
Software support
(step by step procedure) Assessment 2
Fire tests
in Cardington
Structural response
transfer models
(Finite Elemet Methods)
Conclusions
Notes
Lecture 9-1, V001, April 0928
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Principles of step by step procedureObjectives
Repetition
• One-dimensional heat transfer
for the fire unprotected steel elementNominal firecurvesParametric fire
• Equilibrium of increase of temperature of structural element
and heat received on surface of the element in time period Δt
u v
Advanced fire
models
t h Ac V Δθ Δ ρ dnet,mta,aa =The heat
received
on surface
Increase
of en element
temperature
Assessment 1
Thermal response
where
V volume of the element m3 er unit len th
Unprotected steel
Protected steel
Software support
Am surface area of the element [m2] per unit length
c a specific heat of steel [simplified c a = 650 J/kgK]
Assessment 2
Fire tests
in Cardington
ρ a density of steel [ ρ a = 7850 kg/m3 ]
hnet,d net heat flux received by the surface of the element [W/m2 ]
Conclusions
Notes
Lecture 9-1, V001, April 09
me per o max = s
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Step by step procedureObjectives
Repetition
for the fire unprotected steel element in EN 1993-1-2Nominal firecurves
Parametric fire
- ,
the temperature increase in time period Δt is
u v
Advanced fire
models
t hc
m Δ ρ
θ Δ dnet,aa
ta, = Assessment 1Thermal response
where Am /V is the section factor [m-1]
• cannot be used for Am /V smaller than 10 m-1
Unprotected steel
Protected steel
Software support
• w en m s arger an a ou m- ,
the computation gives θ a,t ≅ θ g,t
• the time period Δt should not be longer than 5 s
Assessment 2
Fire tests
in Cardington
The temperature increase depends on the section factor Am /V
Conclusions
Notes
Lecture 9-1, V001, April 09 30
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Thermal propertiesObjectives
Repetition
of carbon steel at elevated temperaturesNominal firecurves
Parametric fire
Specific heat Thermal conductivity
u v
Advanced fire
models
1600
ca [J/kgK]
60
λa [W/mK]
Assessment 1
Thermal response
1200
40
50Unprotected steel
Protected steel
Software support
800
20oC 735
oC
30
20oC
Assessment 2
Fire tests
in Cardington
0 200 400 600 800 1000 1200
θa [oC]
0 200 400 600 800 1000 1200
θa [oC]
Conclusions
Notes
Lecture 9-1, V001, April 0931
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Section factor Am/VObjectives
Repetition
or e re unpro ec e s ee e emen
b
Nominal firecurves
Parametric fire
u v
Advanced fire
models
h
Assessment 1
Thermal response
Perimeter Ex osed erimeter 2 b+h
Unprotected steel
Protected steel
Software support
Area Area Area Assessment 2
Fire tests
in Cardington
Conclusions
NotesThe surface area of the element per unit length of the member
Lecture 9-1, V001, April 0932The figure – I. Burgess, STESSA project
by the volume of the member per unit length .
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Shadow effectObjectives
Repetition
Nominal firecurves
Parametric fire
t hV A
k Δθ Δ dnetmshta/
=
u v
Advanced fire
models
is applied for the total heat flux
c ρ aa
Assessment 1
Thermal response
• k sh
= 1 for hollow sections of convex shape
• k sh = 0,9 ( Am /V )b/ ( Am /V ) for I sections
Unprotected steel
Protected steel
Software support
• k sh = ( Am /V )b/ ( Am /V ) for other sections Assessment 2
Fire tests
in Cardington
For I sections may be simplified
( ) V AV AV A mbmm ///
Conclusions
Notes
Lecture 9-1, V001, April 09
c V Ac t a
ρ ρ dnet,
aam
dnet,
aa
sh,/
,
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Section factor ( Am/V)bObjectives
Repetition
for shadow effect, unprotected steel element
b
Nominal firecurves
Parametric fire
u v
Advanced fire
models
h
Assessment 1
Thermal response
Perimeter Exposed perimeter 2(b+h)
Unprotected steel
Protected steel
Software support
Assessment 2
Fire tests
in Cardington
Conclusions
Notes The box value of the the surface area of the element per unit
length of the member
Lecture 9-1, V001, April 0934The figure – I. Burgess, STESSA project
devided by the volume of the member per unit length.
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Heat fluxObjectives
Repetition
Nominal firecurves
Parametric fire
net
convection and
u v
Advanced fire
models
radiation
Assessment 1
Thermal response
The design value is given by
=
Unprotected steel
Protected steel
Software support
where
r ne ,cne ,ne , Assessment 2
Fire tests
in Cardington
hnet,c is effect off convection, heat flux from convection [W/m2]
hnet,r is effect off radiation, heat flux from radiation [W/m2]
Conclusions
Notes
Lecture 9-1, V001, April 09 35
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Convective heat fluxObjectives
Repetition
2
Nominal firecurves
Parametric fire
mgccnet, θ θ α −=
h
u v
Advanced fire
models
where
Assessment 1
Thermal response
α c s eat trans er coe c ent
• α c = 25 W/m2K for standard curve
Unprotected steel
Protected steel
Software support
• α c = 35 W/m2K for parametric curve
• α c
= 50 W/m2K for hydrocarbon curve
Assessment 2
Fire tests
in Cardington
• α c = 35 W/m2K for zone models and localized fires
θ g is gas temperature in proximity of the element [°C]
Conclusions
Notes
Lecture 9-1, V001, April 09
θ m
is surface temperature of the element [°C]
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Radiative heat fluxObjectives
Repetition
Nominal firecurves
Parametric fire
( ) ( )4
m
48resr net, 2732731067,5 +−+⋅=
−
θ θ ε φ r h
u v
Advanced fire
models
where
Assessment 1
Thermal response
φ is configuration factor, usually φ = 1,0
ε res is resulting emissivity, see next page
Unprotected steel
Protected steel
Software support
θ r is radiating temperature [°C ]
can be taken equal to the gas
Assessment 2
Fire tests
in Cardington
g
θ m is surface temperature of steel element [°C ]
-
Conclusions
Notes
Lecture 9-1, V001, April 09
, · -
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Resultin emissivitObjectives
Repetition
Nominal firecurves
Parametric fire
by amount of carbon particles and dust in the smoke,
and the colour and temperature of the surface.
u v
Advanced fire
models
mf res ε ε ε =
Assessment 1
Thermal response
w ere
ε f is emissivity of f ire, usually ε f = 1,0
Unprotected steel
Protected steel
Software support
ε m is emisivity of material surface for
• carbon steel element ε m = 0,7
Assessment 2
Fire tests
in Cardington
• stainless steel element ε m = 0,4
• aluminum alloys not painted ε m = 0,3
Conclusions
Notes
Lecture 9-1, V001, April 09
• aluminum alloys painted ε m
= 0,7
38
Obj ti
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Techni ue of ste b ste recedureObjectives
Repetition
V A /
Nominal firecurves
Parametric fire
Spreadsheet technique (excel, etc.)Temperature increment
c ρ dnet,
aa
shta, =u v
Advanced fire
models
Gas temperature (according to temperature-time curve)
Com onents of the heat flux S ecific heat
Temperature
of the
element
Assessment 1
Thermal response
t Θ g h net,r h net,c h net,d c a ΔΘ a,t Θ a,t t
of steel at time t TimeUnprotected steel
Protected steel
Software support
min sec min 20,0 J/kg K 20,0
0 0 0 20,0 0 0 0 440 0,00 20,0
0 5 0,083 96,5 448 2679 3126 440 1,18 21,2
0 10 0,167 147,0 937 4402 5339 441 2,00 23,2
0 15 0,250 184,6 1435 5650 7085 442 2,65 25,8
Assessment 2
Fire tests
in Cardington
, , , ,
0 25 0,417 239,7 2412 7374 9787 446 3,63 32,6
0 30 0,500 261,1 2885 7998 10882 449
Conclusions
Notes
Lecture 9-1, V001, April 09 39
Objectives
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Result of ste b ste recedureObjectives
Repetition
Nominal firecurves
Parametric fire
empera ure o upro ec e s ee e emen
heated by nominal standard curve
u v
Advanced fire
models
°
Assessment 1
Thermal response
,
800
Gas temperature,
1000
nominal standard
Unprotected steel
Protected steel
Software support600
Influence of the specific heat leap of steel
Assessment 2
Fire tests
in Cardington
400
npro ec e e emen , sec on
Unprotected element, section IPN 400
Conclusions
Notes
0
200
Lecture 9-1, V001, April 09 40
0 10 20 30 40 50 60 70 Time, min
Objectives
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Result of ste b ste recedureObjectives
Repetition
Nominal firecurves
Parametric fireSteel temperature, °C
of the fire
unprotected
u v
Advanced fire
models900
100150200
40
250
60
stee
θ a,t
Assessment 1
Thermal response700
2025
m m-110 A / V =
15
as function
of time t
Unprotected steel
Protected steel
Software support500
600 ec on ac or
and
section factor
Assessment 2
Fire tests
in Cardington300
400
mConclusions
Notes100
200
Lecture 9-1, V001, April 09 41
Time, min
15 30 45 60 75 900
0
Objectives
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Principle of step by step procedureObjectives
Repetition
for the fire protected steel element
The surface tem erature of fire rotection
Nominal firecurves
Parametric fire
- the same as the gas temperature θ g - θ m
-
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Step by step procedureObjectives
Repetition
or e re pro ec e s ee e emen n - -Nominal firecurves
Parametric fire
( )13/1
/tg,
10/ta,tg,ppta, −−
+
−= θ ΔΔ
φ
θ θ
ρ
λ θ Δ φ et
c d
V A
aa p
u v
Advanced fire
models
where
0ta, ≥θ Δ
V
Ad
c
c pp
aa
pp
ρ
ρ φ =
Assessment 1
Thermal response
λ p is thermal conductivity of the fire protection [W/mK]
A p / V is section factor of fire protected element [m-1]
²
Unprotected steel
Protected steel
Software support
p
d p is thickness of the fire protection [m]
ρ p is density of the fire protection [kg/m3]
Assessment 2
Fire tests
in Cardington
ρ a is density of steel [ ρ a = 7850 kg/m ]
c p is thermal capacity of the fire protection [J kg K]
c a is thermal capacity of steel
Conclusions
Notes
Lecture 9-1, V001, April 09
Δθ g,t is temperature increment in time step Δt
Δt is the time step in seconds, should not be bigger than 30 sec
43
Section factor A /VObjectives
-
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Section factor Ap/VObject es
Repetition
or e re pro ec e s ee e emen
b
Nominal firecurves
Parametric fire
u v
Advanced fire
models
h
Assessment 1
Thermal response
Perimeter
Area2(b+h) Area
Exposedperimeter
Unprotected steel
Protected steel
Software support
Assessment 2
Fire tests
in Cardington
Conclusions
Notes The appropriate area of fire protection material per unit length
of the member
Lecture 9-1, V001, April 0944The figure – I. Burgess, STESSA project
devided by the volume of the member per unit length .
Objectives
-
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Result of ste b ste rocedurej
Repetition
Nominal firecurves
Parametric fire
empera ure o e re pro ec e s ee e emen
heated by nominal standard curve
u v
Advanced fire
models
°
Assessment 1
Thermal response
,
800
Gas temperature
1000
Thickness of fire protectionnominal standard
Unprotected steel
Protected steel
Software support600
10 mm
=p
Assessment 2
Fire tests
in Cardington
400
Conclusions
Notes
0
200
Steel temperature of fire protected element IPN240
Lecture 9-1, V001, April 09 45
0 10 20 30 40 50 60 70 Time, min
Objectives
-
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Result of ste b ste rocedureRepetitionNominal firecurves
Parametric fire
empera ure o e re pro ec e s ee e emen s a,tas function of time t and section factor Ap /V
u v
Advanced fire
models
Temperature, °C
Assessment 1
Thermal response 700
800
35002500
45004000
3000
Unprotected steel
Protected steel
Software support
500
600
800600
1500
1000
Assessment 2
Fire tests
in Cardington300 200
300
Conclusions
Notes 100-3
[W K m ]d V
A
p
p p l -1Section factor
Lecture 9-1, V001, April 09 46
0 30 60 90 120 150 Time, min
Objectives
-
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Repetition Nominal firecurves
Parametric fire
– Step by step procedure
•
u v
Advanced fire
models
– e.g. Heat transfer in steel structures or DIFISEK
– FE modelling
Assessment 1
Thermal response
– The description of tools advantages is summarised in DIFISEK+
database
•
Unprotected steel
Protected steel
Software support
– FE modelling
• Commercial acka es
Assessment 2
Fire tests
in Cardington
– The description of tools advantages is summarised in DIFISEK+
database
Conclusions
Notes
Lecture 9-1, V001, April 09
•
– e.g. for concrete and composite elementsConTemp
47
Objectives
-
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Repetition Nominal firecurves
Parametric fire
• What is the principle of step by step procedure of heat
transfer for the fire unprotected steel element?
u v
Advanced fire
models
• What is influencing the emissivity during the fire?
Assessment 1
Thermal response
• a are e pr nc p es o s ep y s ep proce ure o ea
transfer for the fire protected steel element?
•
Unprotected steel
Protected steel
Software support
and unprotected steel elements? Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 0948
Objectives
-
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Repetition Nominal firecurves
Parametric fire
• The basical findings of European fire research 1980 - 2005
• Fire safety of composite steel to concrete strutures
u v
Advanced fire
models
Outside Inside
Assessment 1
Thermal response
54m
Unprotected steel
Protected steel
Software support
The 1920s
Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 0949
Th lti t b idiObjectives
-
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Three multistore buidin sRepetitionNominal firecurves
Parametric fire
u v
Advanced fire
models
Assessment 1
Thermal response
concrete
composite
building
Unprotected steel
Protected steel
Software support
finished 1994;
plan area 945 m2 Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 0950
Concrete structure
Ei ht fl it b ildiObjectives
-
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Ei ht floors com osite buildinRepetitionNominal firecurves
Parametric fire
21 mu v
Advanced fire
models
Assessment 1
Thermal response
33 m
Unprotected steel
Protected steel
Software support
Assessment 2
Fire tests
in Cardington
Sand bags
Conclusions
Notes
Lecture 9-1, V001, April 0951
Floor plan of composite buildingObjectives
-
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Floor plan of composite buildingRepetitionNominal firecurves
Parametric fire
BRE corner testBS demonstration office test
FE90009000
DC
9000B
9000 A
9000
u v
Advanced fire
models
4
6000305x165x40UB (43)356x171x51UB (50)
356x171x51UB (50)
305x165x40UB (43)305x305x137 UC (50)
Assessment 1
Thermal response
3
9000
Unprotected steel
Protected steel
Software support
2
6000
610x228x101UB (43)
3000
Assessment 2
Fire tests
in Cardington
BS corner testBS restrained beam testBRE large compartment test
BS 2-D cross-frame test
1
Conclusions
Notes
Lecture 9-1, V001, April 09
CTU edge bay test 2003
52
Objectives
-
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Repetition
Nominal fire
curves
Parametric fire
arge sca e re exper men on compos e rameu v
Advanced fire
models
Assessment 1
Thermal response
Unprotected steel
Protected steel
Software support
Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 0953
Restrained beam testObjectives
-
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Restrained beam testRepetitionNominal fire
curves
Parametric fire
1200
Temperature, °C
u v
Advanced fire
models
1000
= Assessment 1
Thermal response
600
800
528
xx
Nominal
standard fire curve
Unprotected steel
Protected steel
Software support
400525
526
x
x
Assessment 2
Fire tests
in Cardington
0
524398x x
Gas temperature
Conclusions
Notes
Lecture 9-1, V001, April 09
me, m n
54
Membrane action of com osite slabObjectives
-
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Membrane action of com osite slabRepetitionNominal fire
curves
Parametric fire One of the develo ments of the Cardin ton laborator wasu v
Advanced fire
models
the development of the models of fire safety of partially
unprotected columns under the composite slab in steel
Compressed area
Assessment 1
Thermal response
.
Unprotected steel
Protected steel
Software support
Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 09
Membrane
55
Objectives
-
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Repetition
4th large scale fire experiment on composite frame
Nominal fire
curves
Parametric fire
u v
Advanced fire
models
Assessment 1
Thermal response
Unprotected steel
Protected steel
Software support
Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 0956
CTU ed e ba testObjectives
R titi
-
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CTU ed e ba testRepetition
7th large scale fire experiment on composite frame
Nominal fire
curves
Parametric fire
• Connection temperatures (a widen MS PowerPoint presentation)
• Connection forces and behavior (a widen MS PowerPoint presentation)
u v
Advanced fire
models
• Composite slab
Assessment 1
Thermal response
Unprotected steel
Protected steel
Software support
Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 0957
Objectives
R titi
-
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Repetition
Nominal fire
curves
Parametric fire
• Describe the basic models of fire.
• What are the major limits of parametric fire curve?
u v
Advanced fire
models
• What is the principle of zone models of fire?
• Describe the models of transfer of heat.
Assessment 1
Thermal response
• What is difference of transfer of heat to the fire protected
and fire unprotected steel element?
Unprotected steel
Protected steel
Software support
• Which material thermal properties of fire protection are
taken into account in evaluation of transfer of heat to the
fire rotected elements?
Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 0958
Objectives
Repetition
-
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Repetition
Nominal fire
curves
Parametric fire
• Simpliest model of fire is a nominal firve curve
• Zone model of fire su orted b software
curves
Advanced fire
models
brings an effective tool for practical design
•
Assessment 1
Thermal response
DIFISEK+
•
Unprotected steel
Protected steel
Software support
temperature is show on a fire test Assessment 2
Fire tests
in Cardington
Conclusions
Notes
Lecture 9-1, V001, April 0959
ConclusionsObjectives
Repetition
-
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ConclusionsRepetition
Nomo ram re ared based on ste b ste rocedure
Nominal fire
curves
Parametric fire
describes the heating of the fire protected and fire unprotected
steel members exposed to nominal standard fire curve.
u v
Advanced fire
models
700800
2000 1500 1000300
200
150 50
[ ]1m mV
A −[ ]Ca °θ⎥⎦
⎤⎢⎣
⎡λ
K m
W
d V
A3
p
p p
Assessment 1
Thermal response
500
600
500400
350
100
75
25
Unprotected steel
Protected steel
Software support
300
400 300
250
200
150
Assessment 2
Fire tests
in Cardington
100
200 100
unprotected
protected
Conclusions
Notes
Lecture 9-1, V001, April 09
0
0 15 30 45 60 75 90 105 120
Fire duration [min]
60
Objectives
Repetition
-
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Repetition
Nominal fire
curves
Parametric fire
• The lecture introduced the bases of modelling
of the compartment fire and transfer of heat into structure
accordin to the Eurocodes.
u v
Advanced fire
models
Assessment 1
Thermal responseFire load
EurocodesFire design
Unprotected steel
Protected steel
Software support
EN 1991-1-2Modelling of the gas temparaturein the fire compartment
Assessment 2
Fire tests
in Cardington
Thermal response
Transfer of heat
Conclusions
Notes
Mechanical load
EN 199x-1-2
- -
Lecture 9-1, V001, April 0961
Design of structure at elevated temparature
Structural response
-
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an you
Lecture 9-1, V001, April 0962
Objectives
Repetition
-
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63/66
p Nominal fire
curves
Parametric fire
• s sess on s a as c n orma on a ou e mo e ng o reand transfer of heat to the structure and requires about 60 minlecturing.
u v
Advanced fire
models
www.access-steel.com and www.difisek.eu.
• The use of relevant standards of national standard institutions
Assessment 1
Thermal response
are strongly recommended.
• Formative questions should be well answered before thesummative questions completed within the tutorial session.
Unprotected steel
Protected steel
Software support
• Keywords for the lecture:
fire design, fire modelling, fire curve, transfer of heat, fire
Assessment 2
Fire tests
in Cardington
, .Conclusions
Notes
Lecture 9-1, V001, April 0963
Objectives
Repetition
-
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Nominal fire
curves
Parametric fire
Worked examples for heat transfer
• The application of the table is in AccessSteel example
u v
Advanced fire
models
• Fire
resistance of a
partially encased composite column
• The application of the graph is in AccessSteel example
Assessment 1
Thermal response
• Fire design of an unprotected beam using graphs
• The description of step by step procedure for heat transfer
Unprotected steel
Protected steel
Software support
• Fire design of an unprotected IPE section beam exposed to the
standard time temperature curve
Assessment 2
Fire tests
in Cardington
• Fire design of a protected HEB section column exposed to the
standard temperature time curve
Conclusions
Notes
Lecture 9-1, V001, April 0964
Objectives
Repetition
-
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Nominal fire
curves
Parametric fire
Worked examples for fire modelling
• The application of the nominal fire curve is in AccessSteel
u v
Advanced fire
models
examp e
• Fire design of an unprotected IPE section beam exposed to thestandard time temperature curve
Assessment 1
Thermal response
• The description of parametric fire curve is in AccessSteelexample
Unprotected steel
Protected steel
Software support
• Parametric fire curve for a fire compartment
• The application of the zone model is in the DIFISEK+
Assessment 2
Fire tests
in Cardington
• WP4 – Software for fire design, slide 10
Conclusions
Notes
Lecture 9-1, V001, April 0965
Objectives
Repetition
-
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66/66
•
Nominal fire
curves
Parametric fire.
• Lecture duration: 60 min
• Keywords: fire design, fire modelling, fire curve, transfer of heat,
u v
Advanced fire
models
fire protection, Eurocodes.
• Aspects to be discussed: high advantage of utilisation ofadvanced fire models, the simplicity of heat transfer by step by
Assessment 1
Thermal response
step procedure and its limits.
• Within the lecturing, the procedure of Eurocode fire design isex lained.
Unprotected steel
Protected steel
Software support
• Further reading: relevant documents from website ofwww.access-steel.com and www.difisek.eu.
Assessment 2
Fire tests
in Cardington
• The reached accuracy in prediction o elemenst temperature isshown on the prediction of the seveth large scale Cardington fire
test.
Conclusions
Notes
Lecture 9-1, V001, April 0966