Cellular Beams

Introduction to Cellular Beams

Dr Stephen Hicks, Manager Structural Systems, HERA,

[email protected]

P. 2

Presentation overview

Manufacturing Process

Applications

Design Software

Recent Research

New Developments

P. 3

2%

15%

68%

10%3%2%

Castellated

Architectural

Straight Rafters

Curved Rafters

Floors

Tapers

UK sales stand at just over

30,000 tonnes p.a. (Nov. 2007)

Range of Applications

P. 4

Manufacturing process

P. 5

Fabrication of cellular beams

Steel beam or column section is cut to create regular

openings

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Oxycutting N°2

HINITIAL Oxycutting N°1

HFINAL

Fabrication of cellular beams

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Final length

Scrap

Fabrication of cellular beams

Flexibility in depth

822 mm deep

cells - 600 dia @ 710 crs

723 mm deep

cells - 450 dia @ 675 crs

Ex 533 x 210 UB 82

Cellular beams pre-cambered mid-production at NO COST

Pre-cambering during the fabricating

process

The parent section is split to create two top tees

Another section is split to create two bottom tees

Asymmetric cellular beam is created by combining tees

Creating Asymmetric Sections

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The cutting profile creates an asymmetric opening position

Asymmetric Openings

By cutting the web along a diagonal and rotating the

bottom tee through 1800 a tapered section is formed.

Production - Creating Tapers

By cutting the web along a diagonal a tapered section can be

formed.

Production - Creating Tapers

Curves formed mid-manufacturing process.

Curves

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Range of Applications – Floor beams

Long, column free spans

Flexibility & more usable floor area

Less foundations

Faster erection

Advantages of long-span construction

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Short Span

9 Beams

Long Span

5 Beams

Reduced fabrication costs

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Short Span Long-span

Quicker Erection

Short Span Long-span

Service Zone

Raised Floor

Service Zone

Raised Floor

Suspended Ceiling

Suspended Ceiling

Depth savings through service

integration

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Service integration with circular ducting

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Incorporation of rectangular services

Cellular beam

Cellular beam with elongated opening

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Elongated openings

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Secondary Beams

9 - 15 m 6 - 9 m

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Secondary beams

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Primary beams

9 - 15 m 6 - 9 m

2.4-3.6 m

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Primary beams

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Cell closures

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Le Colisee Phase II, Paris

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Le Colisee Phase II, Paris

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Le Colisee Phase II- 18.5m span in 470mm

High span/depth ratio (=39)

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0.001

0.010

0.100

1.000

1 10 100

Frequency (Hz)

RM

S A

cc

ele

rati

on

(m

/s²)

BS 6472 Base Curve

R = 4 (0.2%g)

R = 8 (0.4%g)

1.6 Hz along grid-line H

1.6 Hz along grid-line H (with carpet)

2.5 Hz along grid-line H

2.5 Hz along grid-line H (with carpet)

2.5 Hz along grid-line 5

Two men at 1.6 Hz along grid-line H

Two men at 2.5 Hz along grid-line H

Two men at 2.5 Hz along grid-line 5

Running at 2.5 Hz along H

Running at 2.5 Hz along H (with carpet)

Steel Construction

Response Factor

Le Colisee 16.9m Span Floor Area

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Operating Theatres

Clear span

Response factor measured less than 1.0 ( 0.05%g)

See SCI P354

Leeds Nuffield Hospital Cellular Beams

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Cardington design guidance used to

reduce fire protection costs

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Range of Applications – Roof beams

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<20m 30m >40m

Portal (Elastic)

Simply Supported

Straight Rafters

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Bridgewater Car Auction

34.0m span, 92 kg/m castellated beam

Rafters … 800 x 210 x 82 kg/m Cellular

Straight Rafters

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Cyfartha Retail Park, Cardiff

Spans … - 23.0m .. 970 x 229 x 101 kg/m

- 32.0m .. 1056 x 254 x 125 kg/m

- 44.0m .. 1202 x 292 x 176 kg/m

- 53.0m .. 1357 x 305 x 253 kg/m

Simply-supported Curves

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Aldi Distribution Centre, Runcorn. Span 42m

610 x 229 x 101 UB (Plastic design)

700 x 210 x 82 cellular (Elastic design)

Portalised Curved Beams

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Double Curves

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Double Curves

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Tapered Sections

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Over 40 stadia

Mostly Tapered:

Chelsea

Carlisle United

Hull Kingston Stadium

Dunfermline AFC

Newcastle Falcons

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Columns

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Design software

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Support

Yielding orbuckling

Cracking Concretecrushing

Yielding

Compression

Shearforce

Tension

Web-post buckling

Web buckling

Web-postbending

Web-postshear

Modes of Failure at Openings

P. 46

Vierendeel bending at rectangular

opening

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Web-post buckling

P. 48

SCI software

Checks for SCI updates as opened

Cold & Fire Design

SCI QA audit trail down to code level

Import Export with CSC

RAM link underway

Cellbeam Version 6.0

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Design optimization through automate

facility

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Help Screens

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Add moment and axial to the ends

Curved Rafters - With Fixity

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Recent research

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Recent European research programme

Full-scale tests on non-composite and composite beams with regular or isolated web openings to make comparisons with existing software.

Development of generalised design guidance for implementation within European steel and composite Standards, Eurocode 3 and 4 (EN 1993-1-1 and EN 1994-1-1).

Full-scale fire tests on composite beam with regular web openings.

Development of improved manufacturing techniques.

End of spans left

unconcreted to check

influence of local

composite action

7.03 m span length

1.80 m width ( L / 4 )

4 point loads to simulate UDL

Test 1 – Secondary beam with

symmetric cross-section

Test specimen 1 failure modes

Web-post buckling & development of Vierendeel

bending failure observed

Test 2 – Primary beam with symmetric

cross-section

Test 2A

Behaviour at elongated

openings

Test 2B

Load introduction through

secondary beams

Test 2

Load introduction through secondary

beam

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Test 2 failure modes

Test 2A

-Vierendeel bending

developing at elongated

opening

Test 2B

-Excessive yielding in

bottom Tee at mid-span

7.03 m span length

1.80 m width ( ~ L / 4 )

4 point loads

Hybrid beam with Af,b / Af,t = 4

IPE 300 as upper chord

HEB 340 as bottom chord

Test 3 – Secondary beam with

asymmetric cross-section

Test 3 failure modes

Web-post buckling between

openings 11 and 12

Test 4

Test 4 - Influence of stiffening cells in

non-composite beam

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Test 4: Vierendeel mechanism at

opening 4

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Measured failure load vs. predictions

from Cellbeam

Test No Load measured

at failure (kN)

Cellbeam

Predicted

resistance

(kN)

Experimental /

prediction

1

2A

2B

3

4

806

500

780

656

749

540

436

440

276

400

1.49

1.15

1.77

2.38

1.87

P. 64

Test P1: Loaded 7.2 m span composite beam protected with

a cementitious spray - Based on Test 3 specimen tested at University of Kaiserslautern.

Test P2: Unloaded 7.2 m span composite beam with

protected with a cementitious spray - Based on Test 1 specimen tested at University of Kaiserslautern.

In total, 2 fire tests were undertaken at CTICM Test

Station in Maizières-les-Metz :

Full-scale fire tests on composite

cellular beams

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Specimen P1

Specimen P2

Full-scale fire tests on composite

cellular beams

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Specimen P1 and P2 in furnace at

CTICM Test Station Maizières-les-Metz

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Specimen P1 (loaded with jacks) and P2

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Specimen P1 after failure

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Specimen P1 after failure

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Improvement of the welding procedures

Large scale tests

1020

20310

423.7-566.6

PP

1700 - 2000

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1-ss – tw = 8.6 mm, sw = 122mm

2-hs – tw = 8.5/21 mm, sw = 95 mm

3 -ss – tw = 13.5 mm, sw = 63 mm

4-ss – tw = 8.6 mm, sw = 55mm

5-hs – hs – tw = 7.1/21 mm, sw = 55mm

The following 1.7 to 2 m span beam tests were undertaken by

University of Kaiserslautern under the direction of Arcelor

Profil Luxembourg Research:

Improved manufacturing of cellular

beams

P. 72

Specimen

n° Upper Profile

Lower

Profile

Span Length

[mm]

Total Depth

[mm]

Web post width

[mm]

Opening Diameter

[mm]

1-ss IPE 400 IPE 400 1897 558 122 358

2-hs HEA 300 HEM 300 1800 475 95 350

3-ss HEB 400 HEB 400 1940 599 63 422

4-ss IPE 400 IPE 400 1944 600 55 430

5-hs IPE 300 HEM 300 1644 482 55 354

6-ss HEM 300 HEM 300 1559 495 50 334

7-hs HEB 300 HEM 300 1866 472 123 350

8-hs HEA 300 HEB 300 1800 415 147 300

Improvement of the welding procedures

Large scale tests

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Improvement of welding procedures

Large scale tests

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Improvement of welding procedures

Large scale tests

Macrography of weld failure

(web thickness 11/21 mm)

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USFB™

New Developments - Ultra Shallow Floor

Beam

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Or metal deck PC Units

Min 50mm bearing

For Metal Decking

Min 75 mm bearing

For PC Units

USFB™ Made to any depth

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Integrated beams

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Integrated beams with deep decking

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Blackpool – 1.5km of 7.5m long USB

250mm deep 74 kg/m with Comflor deck

USFB™

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Integrated beams with precast hollow

core units

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Conclusions

In the UK, cellular beams are the most popular

form of long-span construction

Long, column free spans are provided which

permit flexibility in the layout and more usable

floor area

Design software is freely available which permits

calculations to be made rapidly

Extensive structural, fire and in situ tests have

been undertaken over the last 10-years to develop

and validate the design software.

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Licensed producers of

Cellular Beams

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Where can I get further information?

Cellbeam (NZ) Ltd

Tel.: +64 (09) 279 7783

Fax: +64 (09) 278 8595

E-mail: [email protected]