Software - Infosteel

Influence of connections on
the cost of steel and
composite building frames
Half study day on economical steel
structures
Prof. J.P. Jaspart, ULg
Organised by Infosteel - Mechelen – 27 April 2011
Contents
• Economical considerations
• Economical studies
• Strategies
• Applications
• Examples for bad and good design
• Design tools
• Publications
• Software
• Worked Example
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Contents
• Economical considerations
• Economical studies
• Strategies
• Applications
• Examples for bad and good design
• Design tools
• Publications
• Software
• Worked Example
3
Economical Considerations
Traditional approach:
frame analysis
assumptions for joint behaviour
M
M
rigid
check of members
pinned
φ
φ
design of joints satisfy assumption
check of joint stiffness ?
often uneconomical solutions !
4
2

Economical Considerations
Modern standards (e.g. Eurocode 3):
Joint design
stiffness model
classification system
semi-rigid joints
Modern design concept:
Integrate joints as structural elements
in the design process
5
Economical Considerations
Strategies for optimum solutions
Savings of fabrication and erection costs
Savings of material costs
Economy studies
France/USA
Belgium
Germany
The Netherlands
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3

Savings of Fabrication Costs
Optimal detailing of rigid joints
Optimize the joint detailing such that the joint stiffness
comes close to the ‘rigid’ classifiaction boundary
M
actual stiffness
rigid
domain
‘rigid’ classification
boundary
φ
7
Savings of Fabrication Costs
Example:
Variations
in detailing
Stiffness
classification
Savings in
fabrication costs
Portal frame
2-3 %
IPE 360
rigid 13 %
7 m
5 m
HEA 300
20 m
IPE 360
65
140 65
46 5
90
90
90
90
360,2
HEA 300
IPE 360
rigid
27 %
HEA 300
200
350
120 IPE 360 rigid 28 %
135 135 10,8
HEA 300
270/716/25
Initial joint detailing
8
4

Savings of Fabrication or Material Costs
Economical benefits from semi-rigid joints
Use semi-rigid joints
in order to have any freedom
to optimize the global frame
and the joint design
M
‘rigid’ classification boundary
semi-rigid
simple joint ?
Simple joints may have
φ
some inherent stiffness and
may transfer moments - take profit of that actual behaviour
9
Economical Studies
France /USA (1991)
by Colson & Bjorhovde
System
unbraced frame
braced frame
Joints
rigid *
semi-rigid
nominally pinned *
semi-rigid
rigid
* reference system
Costs
France USA
100 %
82 % 80 % 18 % 20 %
100 %
Savings
France USA
96 % 105 % 4 % -5 %
120 % 115 % -20 % -15 %
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5

Economical Studies
Belgium
(1995)
by Jaspart &
Guisse
braced
building
frame
unbraced
building
frame
System Joints Savings
flange cleats semi-rigid 3,6 %
ext. end-plate semi-rigid -12,5 %
stiff. ext.
end-plate
ext. end-plate
rigid
semi-rigid
- 48,5 %
20,6 %
braced industrial
frame
flange cleats
ext. end-plate
semi-rigid
semi-rigid
0,7 %
- 2,4 %
reference systems
stiff. ext.
end-plate
rigid
- 18,4 %
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Economical Studies
Germany (1997)
by Weynand
unbraced frame (office building)
w
g = permanent load
p = variable load
s = snow load
w = wind load
g + s
g + p
11,0 m
4,0
4,0
System
unbraced
frame
braced
frame
Joints Company
rigid
semi-rigid 1
semi-rigid 2
pinned
semi-rigid 1
semi-rigid 2
Costs
100 %
76 %
97 %
100 %
96 %
92 %
Savings
24 %
3 %
4 %
8 %
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Economical Studies
in Germany
Joint detailing
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Economical Studies
The Netherlands (1992)
by Steenhuis
Investigated frame (braced)
IPE 300 (pinned)
IPE 270 (partial strength)
4,5 m
4,5 m
IPE 550 (pinned)
IPE 500 (partial strength)
HE220A
HE180A
5,0 m
12 m
12 m
12 m
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Economical Studies
The Netherlands
pinned joints
partial-strength joints
IPE 300
IPE 270
HE 220 A
HE 220 A
Savings =
9 %
IPE 550
IPE 500
HE 220 A
HE 220 A
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Economical Considerations
costs
(not to scale)
total
labour
pinned material S =
rigid
1980
2000
S L j b
EI b
S opt
S
(not to scale)
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Economical Considerations
Conclusions:
Two strategies to minimize the costs
Simplification of joint detailing
Reduction of fabrication costs
Reduction of profile dimensions
Reduction of material costs
Economy studies
Savings in costs of 3 - 20%
dependent on type of frame (bracing)
type of framing (simple/continuous)
steel construction companies
Results confirmed by many studies in various countries
Detailed evaluation of actual costs necessary
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Contents
• Economical considerations
• Economical studies
• Strategies
• Applications
• Examples for bad and good design
• Design tools
• Publications
• Software
• Worked Example
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9

Good and bad design
HE 180 B
V = 62,72 kN
4 x M 20
HE 180 B
3 x M 20
V = 68,41 kN
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Good and bad design
V = 35 kN
V = 35 kN
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10

Good and bad design
M = 98,4 kN
M = 193,9 kN
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Good and bad design
M = 65,4 kN
M = 48,2 kN
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Contents
• Economical considerations
• Economical studies
• Strategies
• Applications
• Examples for bad and good design
• Design tools
• Publications
• Software
• Worked Example
23
Design Tools
Needs for practice:
• Design standards as a basis
• Background information
• Worked examples
• Design tools
- Tables
- Design sheets
- Software
Eurocode 3
Publications
Seminars
Standardised joints
Simplified rules
General application
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Design Tools
Design Books:
Forthcoming ECSC Design Manual
„Design of joints in steel and composite
structures“
• Background
• Design methods & philosophies
• Design sheets
• Design tables
• Worked examples
25
Design Tools
Design Books:
have been prepared recently in:
UK:
Germany:
‘Green Books’ on
- Joints in Simple Constructions
- Moment Connections
DSTV ‘Ringbuch’ on
„Standardised Joints in Building Frames“
- Simple Joints
- Moment Resistant Joints
Cologne Design Tools
The Netherlands: - Design Manual for Simple Joints
- Design Manual for Moment Resistant
Joints
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Design Tools
New issue of DSTV publication on
standardised joints in steel building frames
so-called “Ringbuch”:
„Typisierte Anschlüsse
im Stahlhochbau“
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DSTV Design Tables
Moment resistance
Unstiffened columns
Failure mode
Shear resistance
Beam moment resistance
DIN EC 3
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14

Design Tools
Software
Joint properties
Individual joint
layout
M - φ -curve
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Design Tools
Software:
• Easy input for engineers
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Design Tools
Software:
• Easy input for engineers
• Data check
1. Description of errors
2. Reference to EC 3
3. Possible corrections
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Design Tools
Software:
• Easy input for engineers
• Data check
• Calculation notes
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Design Tools
Software:
• Easy input for engineers
• Data check
• Calculation notes
• Individual language for
user interface / output
33
Design Tools
Software:
• Easy input for engineers
• Data check
• Calculation notes
• Individual language for
user interface / output
• Standard tables included
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Design Tools
Software:
• Easy input for engineers
• Data check
• Calculation notes
• Individual language for
user interface / output
• Standard tables included
• Further components and
flexible configurations
- Haunched beams
- Stiffeners
- Single sided
- Double sided
- Backing plates
- Suppl. web plates
- Simple joints
- Notched beams
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Design Tools
Software:
• Easy input for engineers
• Data check
• Calculation notes
• Individual language for
user interface / output
• Standard tables included
• Further components and
flexible configurations
• Optimisation routines
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Contents
• Economical considerations
• Economical studies
• Strategies
• Applications
• Examples for bad and good design
• Design tools
• Publications
• Software
• Worked Example
37
Worked Example
Software:
Example
Configuration
• Beam IPE 500
• Column HEA 340
• End plate connection
Design assumption
• Rigid joint
Frame analysis
• M Ed = 220 kNm
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Worked Example
Design resistance:
Classification:
Failure mode:
M Rd = 196 kNm < 220 kNm
Semi-rigid
Column web in compression
39
Worked Example
Failure mode:
End plate in bending
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Worked Example
Failure mode:
Column web panel in shear
41
Worked Example
Failure mode:
Column web panel in shear
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Worked Example
Failure mode:
Column web in tension
43
Conclusions
Eurocode 3 is an accepted modern standard
Tools are available and will be further developed
Joint design can become
• economic due to advanced design methods
• easy and quick due to simple tools
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