Tensile membrane action in fire of composite slabs with ...fire- Long Carbon Research Development Tensile membrane action in fire of composite slabs with cellular steel beams Prof

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  • ArcelorMittal Long Carbon

    Research & Development

    Tensile membrane action in fire of composite

    slabs with cellular steel beams

    Prof. Olivier Vassart

  • ArcelorMittal Long Carbon

    Research & Development 2

    FICEB+ - Partnership

  • ArcelorMittal Long Carbon

    Research & Development 3

    Additional fire resistance through 3D

    membrane effect - Bailey's methods extended

    to Long span Cellular Beams

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    Research & Development 4

    Behaviour of slab and beam during a fire

    Composite slab is one-way

    spanning onto unprotected beam

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    Research & Development 5

    Behaviour of slab and beam during a fire

    Plastic hinge forms in unprotected beam

    fan yield line forms in slab

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    Research & Development 6

    Behaviour of slab and beam during a fire

    Strength of composite beam

    continues to reduce

    resulting in the yield pattern shown

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    Research & Development 7

    Behaviour of slab and beam during a fire

    With increasing loss of strength for the beam

    the slab behaviour tends towards a yield line pattern

    given for the slab acting without the beam

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    Research & Development 8

    Load

    capacity

    (bending &

    membrane

    action)

    Temperature

    Strength of slab based on lower

    bound assuming no beam strength

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    Research & Development 9

    X Y

    Z

    Diamond 2008 for SAFIR

    FILE: RealEP

    NODES: 658

    BEAMS: 174

    TRUSSES: 0

    SHELLS: 432

    SOILS: 0

    N1-N2 MEMBRANE FORCE PLOT

    TIME: 2540.639 sec

    - Membrane Force

    + Membrane Force

    Tension

    Compression

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    Research & Development 10

    Horizontal movement

    Fracture

    Compression failure Compression failure

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    Research & Development 11

    15 m 9 m

    3D fire Test

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    Research & Development 12

    Bearing structure

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    Research & Development 13

    Steel sheeting and reinforcement

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    Research & Development 14

    Design Loads

    Description Characteristics

    kN/m2 Load Factor

    Design Load

    kN/m2

    Partition 1.0 1.0 1.0

    Services &

    Finishes 0.5 1.0 0.5

    Live Load 3.5 0.5 1.75

    Total 3.25

    The loads used within the structure are the same as those

    which are commonly used in the design of office buildings.

  • ArcelorMittal Long Carbon

    Research & Development 15

    Fire Loads Toome Test

    Crib Heat Release Rate

    of 1M Wide by 1M Long by 0.5M High Wooden Crib consisting of 44mm2 square section sticks

    -200

    0

    200

    400

    600

    800

    1000

    1200

    1400

    1 75 149 223 297 371 445 519 593 667 741 815 889 963 1037 1111 1185 1259 1333 1407 1481 1555 1629 1703 1777 1851 1925 1999 2073 2147 2221 2295

    Time

    Kilo

    watts (

    kW

    )

    Assuming the design for an office, the fire load density would

    be 511 MJ/m2 according to Table E.2 of EN 1991-1-2.

    For the test, a fire load of 40 kg of wood/m2 was used, which

    corresponds finally to a fire load of about 700 MJ/m.

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    Research & Development 16

    Fire Loads

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    Research & Development 17

    Fire protection

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    Research & Development 18

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    Research & Development 19

    Shape of the beam after the fire

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    Research & Development 20

    Shape of the beam and connection

  • ArcelorMittal Long Carbon

    Research & Development 21

    Additional fire resistance through 3D

    membrane effect Final Method

  • ArcelorMittal Long Carbon

    Research & Development 22

    Additional fire resistance through 3D

    membrane effect Final Method

    Material properties

    0

    0,2

    0,4

    0,6

    0,8

    1

    0 200 400 600 800 1 000 1 200

    Re

    du

    cti

    on

    fa

    cto

    rs

    Temperature ( C)

    kEa,

    kap,

    kay,

    0,0

    0,2

    0,4

    0,6

    0,8

    1,0

    0 200 400 600 800 1 000 1 200

    Re

    du

    cti

    on

    fa

    cto

    rs (x

    1E

    -3)

    Temperature ( C)

    kEa,

    kap,

    kay,

    a) < 600 C b) 600 C and cooling phase

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    Research & Development 23

    Ansys Numerical Model

    B5

    B4

    a) 3D view b) 3D zoom view

    B5

    B4

    B1

    B3

    B2

    c) Bottom view

    Test - beam

    Model 1 slab

    Model1 beamModel 2 slab

    Model 2 - beam

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    Research & Development 24

    SAFIR Numerical Model

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    Research & Development 25

    Numerical simulation

    Vertical displacements

    Realistic modelling?

    Secondary beam: BEAM finite elements

    Secondary beam: SHELL finite element

    Ansys model comparison

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    Research & Development 26

    Numerical simulation

    Model 4: unprotected beams with shell elements

    Temperatures at 90 min (ISO fire)

    C

    Ansys model comparison

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    Research & Development 27

    Numerical simulation

    Model 4: unprotected beams with shell elements

    Temperatures at 90 min (ISO fire)

    C

    Ansys model comparison

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    Research & Development 28

    Numerical simulation

    Model 4: unprotected beams with shell elements

    Vertical displacements at 90 min

    -587 -447 -308 -169 -30 39 (mm) -100 -239 -378 -517

    Ansys model comparison

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    Research & Development 29

    Numerical simulation

    Model 4: unprotected beams with shell elements

    Vertical displacements at 90 min

    -562 -430 -298 -165 -33 33 (mm) -99 -231 -364 -496

    Ansys model comparison

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    Research & Development 30

    Numerical simulation

    Model 4: unprotected beams with shell elements

    Inward lateral torsional buckling

    End

    109 C a 392 C

    Mid-span

    400 C a 636 C

    t = 15 min

    Ansys model comparison

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    Research & Development 31

    Numerical simulation

    Model 4: unprotected beams with shell elements

    Inward lateral torsional buckling

    Mid-span

    667 C a 800 C

    End

    157 C a 540 C

    t = 30 min

    Ansys model comparison

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    Research & Development 32

    Numerical simulation

    Model 4: unprotected beams with shell elements

    Inward lateral torsional buckling

    t = 60 min

    End

    308 C a 883 C

    Mid-span

    963 C a 1 001 C

    Ansys model comparison

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    Research & Development 33

    Numerical simulation

    Model 4: unprotected beams with shell elements

    Inward lateral torsional buckling

    End

    227 C a 710 C

    Mid-span

    876 C a 937 C

    t = 90 min

    Ansys model comparison

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    Research & Development 34

    Numerical simulation

    Comparison of the 4 numerical models

    Vertical deflections

    Simplified kept model : model 4

    Unprotected secondary beam

    Slab

    -500

    -450

    -400

    -350

    -300

    -250

    -200

    -150

    -100

    -50

    0

    0 10 20 30 40 50 60 70 80 90Temps (min)

    Fl

    ch

    e d

    e l

    a s

    oli

    ve

    in

    tri

    eu

    re (

    mm

    )

    Modle 1

    Modle 2

    Modle 3

    Modle 4b

    Defl

    ecti

    on

    of

    the u

    np

    rote

    cte

    d b

    eam

    (m

    m)

    Time (min)

    -700

    -600

    -500

    -400

    -300

    -200

    -100

    0

    0 10 20 30 40 50 60 70 80 90Temps (min)

    Fl

    ch

    e d

    e l

    a d

    all

    e (

    mm

    )

    Modle 1

    Modle 2

    Modle 3

    Modle 4b

    Defl

    ecti

    on

    of

    the s

    lab

    (m

    m)

    Time (min)

    Ansys model comparison

  • ArcelorMittal Long Carbon

    Research & Development 35

    RFCS MACS+ Software

  • ArcelorMittal Long Carbon

    Research & Development 4/17/2012 36

    THE NATIONAL SEMINARS OBJECTIVES

    to distribute the produced data to the practitioners in order that

    they become aware of what are the advantages of the

    membrane effect as of its applicability

    SEMINARS

    MACS+

    RFCS MACS+ Seminars

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    Research & Development 37

    Thank you for

    your