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New developments in cold-formed
steel construction
Jurgen Becque
Iman Hajirasouliha
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
Cold-formed steel research at the University of Sheffield
Who are we ?
Academics
Associate members
Dr Jurgen Becque
Dr Hassan Ghadbeigi
Dr Iman Hajirasouliha
Dr Rachel Cruise
Post-doctoral researcher
Dr Shan-Shan Huang
Dr Shanshan Cheng
PhD students
Jun Ye
Francisco Meza
Xilin Li
Hao Wen
Seyed Mojtabaei
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
What is cold-formed steel ?
Roll forming
Ambient temp.
Press brake
http://www.americanmachinetools.com/press_brake.htm
http://www.rollerdie.com/roll-forming/
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
Advantages of cold-formed steel
• High strength-to-weight ratio
efficient material use
• Light weight
•
Easy to handle, transport, stack
•
High construction speeds
• Durable (galvanized)
• Recyclable
• Straightforward and versatile manufacturing process
Disadvantages
• Susceptible to cross-sectional instabilities
• Difficult to design
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
Instabilities in cold-formed steel
L
D
G
O
IStructE Yorkshire technical presentations
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New trends in cold-formed steel
1
Innovative new cross-sections with complex geometries
2
New design methods for cold-formed steel structural
elements
3
Cold-formed steel as primary load bearing members:
• Multi-storey buildings
• Portal frames
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
Innovative cross-sections with complex geometries
http://www.bluescopesteel.com.au/files/dmfile/SupaZedSupaCeeJ
an071.pdf
http://www.hadleygroup.com/loads-better-purlin-and-side-railsystem/new-ultrazed-2-purlin.aspx
IStructE Yorkshire technical presentations
UltraZED
UltraBEAM
Sheffield, 16 May 2016
Innovative cross-sections with complex geometries
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
New trends in cold-formed steel
1
Innovative new cross-sections with complex geometries
2
New design methods for cold-formed steel structural
elements
3
Cold-formed steel as primary load bearing members:
• Multi-storey buildings
• Portal frames
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
New design methods for cold-formed steel
Current EC3-1-3 design rules are based on the effective width
concept:
Leads to lengthy and iterative calculations for complex
geometries.
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
New design methods for cold-formed steel
The Direct Strength Method (DSM):
 
fy
 el

Py
Pel
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
New design methods for cold-formed steel
Elastic stability analysis:
IStructE Yorkshire technical presentations
CUFSM (Finite Strip Method)
Sheffield, 16 May 2016
New trends in cold-formed steel
1
Innovative new cross-sections with complex geometries
2
New design methods for cold-formed steel structural
elements
3
Cold-formed steel as primary load bearing members:
• Multi-storey buildings
• Portal frames
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
Application of cold-formed steel
Traditionally: secondary members: purlins, side rails, stud walls, ...
IStructE Vorkshire technical presentations
Sheffield,16 May 2016
New applications for cold-formed steel
http://www.buildings.com/news/industry-news/articleid/10392/title/coldformed-steel-improvements-ideal-for-framing-solutions.aspx
http://www.newsteelconstruction.com/wp/best-practice-for-light-steel-framing/
Multi-storey CFS buildings
(up to 7-8 storeys)
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
New applications for cold-formed steel
IStructE Vorkshire technical presentations
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New applications for cold-formed steel
Cold-formed steel
portal frames
http://www1.ruukki.com/Construction/System-halls/System-hall-solution-Spider
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
The future of cold-formed steel
Construction Leadership Council (CLC):
By working in partnership, the construction industry and Government jointly aspire to
achieve by 2025:
1.
A 33% reduction in both the initial cost of construction and the whole life
cost of assets1
2.
A 50% reduction in the overall time from inception to completion for new
build and refurbished assets2
3.
A 50% reduction in greenhouse gas emissions in the built environment3
4.
A 50% reduction in the trade gap between total exports and total imports for
construction products and materials4
These are long-term ambitions shared by industry and Government jointly. The
Construction Leadership Council will develop an action plan to achieve these
ambitions between now and 2025.
https:/I www.gov.uk/gavernment/ uploads/system/u ploads/attachment_data/f ile/210099/bis-13-955-construction-202 5-indust ria1-st rategy.pdf
IStructE Vorkshire technical presentations
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The future of cold-formed steel
The quest for longer spans:
2
1
Composite steel-concrete
Built-up sections
3
Composite steel-CLT
IStructE Yorkshire technical presentations
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Cold-formed steel with CLT
Cold-formed steel – CLT hybrid construction
Loss, C., Piazza, M., and Zandonini, R. (2015). “Connections for steel–timber hybrid
prefabricated buildings. Part I: Experimental tests.” Construction and Building
Materials, in press.
IStructE Yorkshire technical presentations
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Built-up cold-formed steel sections
Specimen geometry :
Outer channels
Channels
Plate
sections
Inner channels
12 Stub columns with three different connector spacings
IStructE Yorkshire technical presentations
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Built-up cold-formed steel sections
Material properties
200
Machined
corner
57
63
re
20
63
12.5
Square bar
12.5
ri
Corner coupons
120
40
t
32
40
b
10
6
6
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
Built-up cold-formed steel sections
Geometric imperfections
Laser sensor
Traverse system
IStructE Yorkshire technical presentations
Flat table
Sheffield, 16 May 2016
Built-up cold-formed steel sections
Measuring geometric imperfections
Left
Left
Middle
Right
Right
Middle
Corner
Tip
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
Built-up cold-formed steel sections
Results for built-up column 1:
Built-up geometry 1
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
Built-up cold-formed steel sections
Results for built-up column 2:
Built-up geometry 2
2 connectors
4 connectors
IStructE Yorkshire technical presentations
6 connectors
Sheffield, 16 May 2016
Built-up cold-formed steel sections
Built-up geometry 1
Built-up geometry 2
250
250
10.81%
SC2-2a
SC1-2b
SC2-2b
200
SC1-3a
SC2-4a
SC2-4b
SC1-3b
150
SC1-5a
SC1-5b
100
50
Force (kN)
Force (kN)
200
SC1-2a
SC2-6a
150
SC2-6b
100
50
0
0
0
2
4
6
8
10
12
Axial displacement (mm)
IStructE Yorkshire technical presentations
14
0
2
4
6
8
10
12
14
Axial displacement (mm)
Sheffield, 16 May 2016
Built-up cold-formed steel sections
Finite element modelling:
2 connectors
3 connectors
IStructE Yorkshire technical presentations
5 connectors
Sheffield, 16 May 2016
Built-up cold-formed steel sections
Load vs. axial shortening diagrams (column 2)
Built-up geometry 2
Test
FE Model
250
200
)
150
kN
( 150
e
c
r 100
Fo 100
50
50
50
50
Force (kN)
00
200
)
150
kN
( 150
ce
100
100
For
Force (kN)
200
)
150
kN
(
e
c
r 100
Fo 100
250
00
22
44
66
88
10
10
00
Force (kN)
250
50
00
Axial
Axial displacement
displacement (mm)
(mm)
2 connectors
IStructE Yorkshire technical presentations
22
44
66
88
Axial
Axial displacement
displacement (mm)
(mm)
4 connectors
10
10
0
0
2
4
6
8
Axial displacement (mm)
6 connectors
Sheffield, 16 May 2016
10
Built-up cold-formed steel sections
12 Built-up beams with three different connector spacings
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
Built-up cold-formed steel sections
IStructE Vorkshire technical presentations
Sheffield,16 May 2016
Built-up cold-formed steel sections
Built-up geometry 1
Built-up geometry 2
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016
Thank You !
IStructE Yorkshire technical presentations
Sheffield, 16 May 2016