cold form design in scia.pdf
TRANSCRIPT
Apollo Bridge
Architect: Ing. Miroslav Maťaščík - Alfa 04 a.s., Bratislava
Design: Dopravoprojekt a.s., Bratislava
Apollo Bridge
Architect: Ing. Miroslav Maťaščík - Alfa 04 a.s., Bratislava
Design: DOPRAVOPROJEKT a.s., Bratislava
Aluminium & Cold-Formed Steel
in Scia Engineer
User Meeting Salzburg 5 november 2010 ing. Peter Van Tendeloo – Product Development Engineer
1
Contents
1. National Annex for Steel and Aluminium
2. Aluminium according to EN 1999-1-1
3. Cold-formed steel according to EN 1993-1-3
4. Small improvements in Steel
5. Benchmarks EN 1993
2
National Annex
1. National Annex for Steel and Aluminium
3
National Annex
4
National Annex
- What has been implemented?
- Which method is supported?
- How exactly is this parameter used?
-…
=> Theoretical Backgrounds
5
National Annex
6
Aluminium
2. Aluminium according to EN 1999-1-1
7
Aluminium
General design differences between Steel and Aluminium:
Steel Aluminium
- Welds are strong points - Welds weaken the material
- Classification for combined effects - Separate classification per component
- Effective width - Effective thickness
- Buckling curve depending on section - Buckling curve depending on material
(only slightly on material)
8
Aluminium
Effect of welds
Material properties according to art. 3.2.2
Theory
9
Aluminium
Effect of welds
Material properties according to art. 3.2.2
Scia Engineer
10
Aluminium
Classification
Classification according to art. 6.1.4
Theory – Definition of cross-section parts
11
Aluminium
Classification
Classification according to art. 6.1.4
Theory – Definition of slenderness limits
12
Aluminium
Classification
Classification according to art. 6.1.4
Scia Engineer – Definition of initial shape & welds
13
Aluminium
Classification
Classification according to art. 6.1.4
Scia Engineer – Slenderness limits and classification for N-
14
Aluminium
Effective section
Effective section according to art. 6.1.4
Theory – Reduction factors
The following reduction factors are calculated:
1. Local Buckling: Reduction factor ,c
2. Distortional Buckling: Reduction factor
3. HAZ effects: Reduction factor ,HAZ
Additional reduction for
distortional buckling:
15
Aluminium
Effective section
Effective section according to art. 6.1.4
Theory – Local Buckling ,c
16
Aluminium
Effective section
Effective section according to art. 6.1.4 & TALAT Lecture 2301
Theory – Distortional Buckling
17
Aluminium
Effective section
Effective section according to art. 6.1.4 & TALAT Lecture 2301
Theory – Distortional Buckling
18
Aluminium
Effective section
Effective section according to art. 6.1.4
Theory – Welding Effects ,HAZ
MIG:
TIG:
19
Aluminium
Effective section
Effective section according to art. 6.1.4
Theory – Effective section
Additional reduction for
distortional buckling:
20
Aluminium
Effective section
Effective section according to art. 6.1.4
Scia Engineer – Effective section for N-
Section with weld in the middle of the web
21
Aluminium
Effective section
Effective section according to art. 6.1.4
Scia Engineer – Effective section for My+
Section with weld in the middle of the web
22
Aluminium
Effective section
Effective section according to art. 6.1.4
Scia Engineer – Effective sections
Initial Shape Effective shape N- Effective shape My+
23
Aluminium
Effective section
Effective section according to art. 6.1.4
Scia Engineer – Effective section properties
24
Aluminium
Effective section
Effective section according to art. 6.1.4
Scia Engineer – General Cross-section
Gross section
Used for gross-section properties
Thinwalled representation
Used for classification and effective section properties
25
Aluminium
Effective section
Effective section according to art. 6.1.4
Scia Engineer – General Cross-section
26
Aluminium
Effective section
Effective section according to art. 6.1.4
Scia Engineer – General Cross-section
27
Aluminium
Section Checks
Section Checks according to EN 1999-1-1
art. 6.2.3. Tension
art. 6.2.4. Compression
art. 6.2.5. Bending Moment
art. 6.2.6. Shear
art. 6.2.7. Torsion
art. 6.2.8. Bending and shear
art. 6.2.9. Bending and axial force
art. 6.2.10. Bending , shear and axial force
28
Aluminium
Section Checks
Bending Check according to art. 6.2.5
Theory
These are NOT National Annex Parameters !!!
29
Aluminium
Section Checks
Bending Check according to art. 6.2.5
Scia Engineer
Choice of alternative values:
30
Aluminium
Section Checks
Bending Check according to art. 6.2.5
Scia Engineer
Default Alternative
31
Aluminium
Section Checks
Shear Check according to art. 6.2.6
Theory
General theory according to art. 6.5.5
32
Aluminium
Section Checks
Shear Check according to art. 6.2.6 & 6.5.5
Scia Engineer
Section with no slender elements Section with slender elements
33
Aluminium
Section Checks
Bending and axial force according to art. 6.2.9
Theory
34
Aluminium
Section Checks
Bending and axial force according to art. 6.2.9
Theory
35
Aluminium
Section Checks
Bending and axial force according to art. 6.2.9
Scia Engineer – No Transverse weld
36
Aluminium
Section Checks
Bending and axial force according to art. 6.2.9
Scia Engineer – Input of Transverse weld
37
Aluminium
Section Checks
Bending and axial force according to art. 6.2.9
Scia Engineer – With Transverse weld
38
Aluminium
Stability Checks
Stability Checks according to EN 1999-1-1
art. 6.3.1. Members in compression
art. 6.3.2. Members in bending
art. 6.3.3. Members in bending and axial compression
art. 6.7.4.2, 6.7.6.1 Shear buckling
39
Aluminium
Stability Checks
Members in compression according to art. 6.3.1
Theory – Flexural Buckling
40
Aluminium
Stability Checks
Members in compression according to art. 6.3.1
Scia Engineer – Flexural Buckling
41
Aluminium
Stability Checks
Members in compression according to art. 6.3.1
Theory – Torsional (-Flexural) Buckling
General Theory
42
Aluminium
Stability Checks
Members in compression according to art. 6.3.1
Theory – Torsional (-Flexural) Buckling
43
Aluminium
Stability Checks
Members in compression according to art. 6.3.1
Scia Engineer – Torsional (-Flexural) Buckling
44
Aluminium
Stability Checks
Members in bending and axial compression according to art. 6.3.3
Theory
45
Aluminium
Stability Checks
Members in bending and axial compression according to art. 6.3.3
Theory - Welds
46
Aluminium
Stability Checks
Members in bending and axial compression according to art. 6.3.3
Theory – Design factors and xs distance
47
Aluminium
Stability Checks
Members in bending and axial compression according to art. 6.3.3
Scia Engineer
48
Aluminium
Stability Checks
Members in bending and axial compression according to art. 6.3.3
Scia Engineer – Determination of xs
Choice of method:
xs is the distance from the studied section to a simple support or point of contra flexure of the
deflection curve for elastic buckling of axial force only
49
Aluminium
Stability Checks
Members in bending and axial compression according to art. 6.3.3
Scia Engineer – Determination of xs
50
Aluminium
National Annex
Few countries have published an NA to EN 1999-1-1 and those who have do not diverge of the EN defaults.
51
Aluminium
Theoretical Background
- What has been implemented?
- Which method is supported?
- How exactly is this parameter used?
-…
=> Theoretical Backgrounds
52
Cold-Formed
3. Cold-Formed steel according to EN 1993-1-3
53
Cold-Formed
Materials
54
Cold-Formed
Cross-section
Example: Sadef C 200 x 3.00 S390GD + Z
Core thickness EN 1993-1-3 art. 3.2.4 due to zinc coating
Nominal thickness 3 mm
Core thickness = 2,96 mm
This thickness must be used in design !
Recalculated properties of the gross section
55
Cold-Formed
May EN 1993-1-3 be applied?
May EN 1993-1-3 be applied without additional tests?
Remark: the condition for the core thickness is a Nationally Determined Parameter !
Default EN:
Austrian National Annex:
Dutch National Annex:
German National Annex:
Scia Engineer
Choice of NA
a) Condition for the core thickness: EN 1993-1-3 art. 3.2.4(1)
56
Cold-Formed
May EN 1993-1-3 be applied?
May EN 1993-1-3 be applied without additional tests?
c) Conditions for the stiffeners: EN 1993-1-3 art. 5.2(2)
b) Conditions for the section geometry: EN 1993-1-3 art. 5.2(1)
57
Cold-Formed
May EN 1993-1-3 be applied?
May EN 1993-1-3 be applied without additional tests?
Scia Engineer
58
Cold-Formed
Effective section
The calculation of the effective section can be split in the following steps:
A) Determination of the notional width of the elements
B) Local buckling of the elements in compression
C) Distortional buckling of the stiffeners with optional iterations
D) Optional: Iterative calculation of the full cross-section
59
Cold-Formed
A) Determination of the notional width
Influence of rounded corners according to EN 1993-1-3 art. 5.1
Theory
60
Cold-Formed
A) Determination of the notional width
Influence of rounded corners according to EN 1993-1-3 art. 5.1
Scia Engineer
Generation of the initial shape
61
Cold-Formed
A) Determination of the notional width
Influence of rounded corners according to EN 1993-1-3 art. 5.1
Scia Engineer
Generation of the initial shape and calculation of the notional width
62
Cold-Formed
B) Local buckling of elements in compression
Local buckling according to EN 1993-1-5 art. 4.4
Theory
Warning: Correction sheet EN 1993-1-5:2006/AC:2009
Local buckling according to EN 1993-1-3 art. 5.5.2
63
Cold-Formed
B) Local buckling of elements in compression
Local buckling according to EN 1993-1-5 art. 4.4
Scia Engineer
Calculation of the effective width for My-
64
Cold-Formed
C) Distortional buckling of stiffeners with optional iterations
Distortional buckling according to EN 1993-1-3 art. 5.5.3
Theory
The real geometry is replaced by an equivalent system with translation spring K
65
Cold-Formed
C) Distortional buckling of stiffeners with optional iterations
Distortional buckling according to EN 1993-1-3 art. 5.5.3
Theory
The effective geometry of the stiffener and the translation spring K are used
for the calculation of the critical buckling stress cr,s of the stiffener.
Default formula for the critical buckling stress of a “beam on elastic foundation”
66
Cold-Formed
C) Distortional buckling of stiffeners with optional iterations
Distortional buckling according to EN 1993-1-3 art. 5.5.3
Theory
The critical buckling stress cr,s of the stiffener is used for the calculation of
the relative slenderness and the reduction factor d.
67
Cold-Formed
C) Distortional buckling of stiffeners with optional iterations
Distortional buckling according to EN 1993-1-3 art. 5.5.3
Theory – General procedure
68
Cold-Formed
C) Distortional buckling of stiffeners with optional iterations
Distortional buckling according to EN 1993-1-3 art. 5.5.3
Theory – General procedure
69
Cold-Formed
C) Distortional buckling of stiffeners with optional iterations
Distortional buckling according to EN 1993-1-3 art. 5.5.3
Theory – General procedure – Remark
Remark: the safety factors are Nationally Determined Parameters !
Default EN:
Austrian National Annex:
Dutch National Annex:
German National Annex:
Scia Engineer
Choice of NA
70
Cold-Formed
C) Distortional buckling of stiffeners with optional iterations
Distortional buckling according to EN 1993-1-3 art. 5.5.3
Scia Engineer
Optional iterations of the stiffeners
Distortional buckling of the stiffeners with influence on local buckling
71
Cold-Formed
D) Optional: Iterative calculation of the full cross-section
Iterations of the full cross-section according to EN 1993-1-3 art. 5.5.2
Theory
72
Cold-Formed
D) Optional: Iterative calculation of the full cross-section
Iterations of the full cross-section according to EN 1993-1-3 art. 5.5.2
Scia Engineer
Optional iterations of the full cross-section
Final effective section
Effective section properties
73
Cold-Formed
D) Optional: Iterative calculation of the full cross-section
Iterations of the full cross-section according to EN 1993-1-3 art. 5.5.2
Scia Engineer
Final effective section
74
Cold-Formed
Effective section
Scia Engineer – General Cross-section
Input of any thinwalled shape Calculation of effective section
75
Cold-Formed
Section Checks
Section Checks according to EN 1993-1-3
art. 6.1.2. Axial Tension
art. 6.1.3. Axial Compression
art. 6.1.4. Bending Moment
art. 6.1.5. Shear Force
art. 6.1.6. Torsional Moment
art. 6.1.7. Local Transverse Forces
art. 6.1.8. Combined Tension and Bending
art. 6.1.9. Combined Compression and Bending
art. 6.1.10. Combined Shear, Axial force and Bending Moment
art. 6.1.11. Combined Bending and Local Transverse Force
76
Cold-Formed
Section Checks
Bending Check according to EN 1993-1-3 art. 6.1.4
Theory
77
Cold-Formed
Section Checks
Bending Check according to EN 1993-1-3 art. 6.1.4
Scia Engineer
78
Cold-Formed
Section Checks
Shear Check according to EN 1993-1-3 art. 6.1.5
Theory
79
Cold-Formed
Section Checks
Shear Check according to EN 1993-1-3 art. 6.1.5
Scia Engineer
80
Cold-Formed
Section Checks
Local Transverse Forces Check according to EN 1993-1-3 art. 6.1.7
Theory
81
Cold-Formed
Section Checks
Local Transverse Forces Check according to EN 1993-1-3 art. 6.1.7
Scia Engineer
Default Bearing Length in the Steel Setup:
Advanced modifications through additional data:
82
Cold-Formed
Section Checks
Local Transverse Forces Check according to EN 1993-1-3 art. 6.1.7
Scia Engineer
83
Cold-Formed
Section Checks
Combined Bending and Local Transverse Force according to EN 1993-1-3 art. 6.1.11
Theory
84
Cold-Formed
Section Checks
Combined Bending and Local Transverse Force according to EN 1993-1-3 art. 6.1.11
Scia Engineer
85
Cold-Formed
Stability Checks
Stability Checks according to EN 1993-1-3
art. 6.2.2. Flexural buckling
art. 6.2.3. Torsional and Torsional-Flexural buckling
art. 6.2.4. Lateral-Torsional buckling
art. 6.2.5. Bending and axial compression
art. 6.3. Bending and axial tension
86
Cold-Formed
Stability Checks
Bending and axial compression according to EN 1993-1-3 art. 6.2.5
Theory
Note: This is not a National Annex Parameter !
87
Cold-Formed
Stability Checks
Bending and axial compression according to EN 1993-1-3 art. 6.2.5
Scia Engineer
88
Cold-Formed
Stability Checks
Bending and axial tension according to EN 1993-1-3 art. 6.3
Theory
Theory according to AISI NAS 2007 art. C5
89
Cold-Formed
Stability Checks
Bending and axial tension according to EN 1993-1-3 art. 6.3
Scia Engineer
90
Cold-Formed
Special condiderations for beams (purlins) restrained by sheeting
Theory
May EN 1993-1-3 Chapter 10 be applied?
a) Conditions for cross-section dimensions: EN 1993-1-3 art. 10.1.1(1)
b) Condition for the shear stiffness of the diaphragm: EN 1993-1-3 art. 10.1.1(6)
91
Cold-Formed
Special condiderations for beams (purlins) restrained by sheeting
Scia Engineer
May EN 1993-1-3 Chapter 10 be applied?
Calculation of the shear stiffness using test data of the manufacturer:
92
Cold-Formed
Special condiderations for beams (purlins) restrained by sheeting
Theory
Beam restrained by sheeting – Principle according to EN 1993-1-3 art. 10.1.2
The purlin, restrained by sheeting, is replaced by a beam on elastic foundation
Compare with the calculation of distortional buckling: same principle!
93
Cold-Formed
Special condiderations for beams (purlins) restrained by sheeting
Theory
Beam restrained by sheeting – Resistance of the cross-section according to EN 1993-1-3 art. 10.1.4.1
94
Cold-Formed
Special condiderations for beams (purlins) restrained by sheeting
Theory
Beam restrained by sheeting – Resistance of the cross-section according to EN 1993-1-3 art. 10.1.4.1
a) Determine the geometry of the ‘free flange’
b) Determine the equivalent horizontal loading
95
Cold-Formed
Special condiderations for beams (purlins) restrained by sheeting
Theory
Beam restrained by sheeting – Resistance of the cross-section according to EN 1993-1-3 art. 10.1.4.1
c) Determine the lateral spring stiffness
96
Cold-Formed
Special condiderations for beams (purlins) restrained by sheeting
Theory
Beam restrained by sheeting – Resistance of the cross-section according to EN 1993-1-3 art. 10.1.4.1
d) Determine the equivalent bending moment
Remark: The table only gives some values, for an exact calculation the theory of Winkler
may be used for beams on elastic foundation.
97
Cold-Formed
Special condiderations for beams (purlins) restrained by sheeting
Theory
Beam restrained by sheeting – Resistance of the cross-section according to EN 1993-1-3 art. 10.1.4.1
d) Determine the equivalent bending moment
=> See Theoretical Background for other solutions
98
Cold-Formed
Special condiderations for beams (purlins) restrained by sheeting
Scia Engineer
Beam restrained by sheeting – Resistance of the cross-section according to EN 1993-1-3 art. 10.1.4.1
Calculation of the rotational stiffness of the sheeting:
Geometry of the „free flange‟:
99
Cold-Formed
Special condiderations for beams (purlins) restrained by sheeting
Scia Engineer
Beam restrained by sheeting – Resistance of the cross-section according to EN 1993-1-3 art. 10.1.4.1
100
Cold-Formed
Special condiderations for beams (purlins) restrained by sheeting
Theory
Beam restrained by sheeting – Buckling resistance of the free flange according to EN 1993-1-3 art. 10.1.4.2
Remark: the method for LT concerns a Nationally Determined Parameter !
British National Annex:
Austrian National Annex:
Scia Engineer
Choice of NA
101
Cold-Formed
Special condiderations for beams (purlins) restrained by sheeting
Theory
Beam restrained by sheeting – Buckling resistance of the free flange according to EN 1993-1-3 art. 10.1.4.2
102
Cold-Formed
Special condiderations for beams (purlins) restrained by sheeting
Scia Engineer
Beam restrained by sheeting – Buckling resistance of the free flange according to EN 1993-1-3 art. 10.1.4.2
103
Cold-Formed
Theoretical Background
- What has been implemented?
- Which method is supported?
- How exactly is this parameter used?
-…
=> Theoretical Backgrounds
104
Small Improvements
4. Small improvements in Steel
105
Small Improvements
Scia Engineer
Table for defining the reduction of the yield strength in function of the thickness
106
Small Improvements
Scia Engineer
Re-organisation of the Steel tree
107
Small Improvements
Scia Engineer
Clear outputs of the stability checks
108
Small Improvements
Scia Engineer
Shortened outputs of the stability checks
109
Small Improvements
Scia Engineer
LTB outputs for CHS and RHS sections
CHS sections
RHS sections
110
Small Improvements
Theory
Modified Design rule for LTB of Channel sections
111
Small Improvements
Scia Engineer
Modified Design rule for LTB of Channel sections
112
Small Improvements
Theory – EN 1993-1-1 art. 5.2.2(7)
2nd order: Buckling lengths taken equal to system lengths
113
Small Improvements
Scia Engineer
2nd order: Buckling lengths taken equal to system lengths
All non-sway
l = L
114
Small Improvements
Theory – EN 1993-1-3 art. 5.5.1(7)
Cold-Formed: Manual input of buckling stresses
115
Small Improvements
Theory – EN 1993-1-3 art. 5.5.1(7)
Cold-Formed: Manual input of buckling stresses
116
Small Improvements
Theory
Cold-Formed: Manual input of buckling stresses
Calculation of Local and Distortional Buckling stresses using for example CUFSM
117
Small Improvements
Theory
Cold-Formed: Manual input of buckling stresses
Calculation of Local and Distortional Buckling stresses using for example CUFSM
118
Small Improvements
Scia Engineer
Cold-Formed: Manual input of buckling stresses
Input of Local and Distortional Buckling stresses
119
Small Improvements
Scia Engineer
Cold-Formed: Manual input of buckling stresses
120
Benchmarks
5. Benchmarks EN 1993
121
Benchmarks
122
Benchmarks
123
Benchmarks
124
Benchmarks
125
Benchmarks
126
Thank You
Thank you for your attention!