One-Day Research Showcase
November 14th 2006, DAPS, Naples
Advanced Materials & Systems
Composite Structures in Seismic Regions
L. Di Sarno
University of Sannio, Benevento, Italy
Outline
• Introduction
• Displacement Based Design
• Experimental Tests
• Numerical Simulations
• Final Remarks
November 14, 2006, DAPS, Naples, Italy
Introduction
Ongoing Research Projects @ UniSannio
Partial Interaction in Composite Structures
PI: Marisa Pecce
Budget: 36k USD
Duration: 2yrs (2004-2006)
Rotation capacity of composite members
PI: Marisa Pecce
Budget: 100k USD
Duration: 2yrs (2005-2008)
Displacement Based Design of Composite Structures
PI: Luigi Di Sarno
Deformation Capacity
Experimental Tests
Budget: 36k USD
Numerical Simulations
Sub-assemblages
November 14, 2006, DAPS, Naples, Italy
Displacement Based Design
Local and global ductility (e.g. rotations & interstoreys d/h)
For framed systems the collapse mechanism mode is linear (global mechanism).
Sub-structuring
N
N
VVcc
VFb t
Ftb
V
VVc c
LL
N
N
Η
H
sag
Δ = Δhog
beam + Δ beam + Δ col + Δ jo int
November 14, 2006, DAPS, Naples, Italy
Composite Interactions
Beam type A
#20 shear studs
Spacing 190 mm
Beam type B
#2*10 shear studs
Spacing 190 mm
Members
Connections
Beam type C
Spacing 515 mm
Span length 3610 mm
Asymmetric Response
Components
#8 shear studs
RC
Full
Interaction
Steel
Partial
November 14, 2006, DAPS, Naples, Italy
Displacement-Based Design
Sample Frames
MRF
Pianta piano tipo
31,00
7,00
6,00
5,00
6,00
Rigid Connections
9-storeys
7,00
IPE 360
HE B VAR
IPE 360
HE B VAR
IPE 360
HE B VAR
IPE 360
HE B VAR
IPE 360
HE B VAR
IPE 360
IPE 140
IPE 360
IPE 360
HE B VAR
IPE 360
HE B VAR
IPE 360
HE B VAR
IPE 360
HE B VAR
IPE 360
HE B VAR
IPE 360
HE B VAR
IPE 360
HE B VAR
IPE 360
HE B VAR
IPE 360
HE B VAR
IPE 360
HE B VAR
IPE 360
HE B VAR
HE B VAR
IPE 360
HE B VAR
HE B VAR
IPE 360
HE B VAR
HE B VAR
IPE 360
HE B VAR
HE B VAR
IPE 360
HE B VAR
IPE 140
HE B VAR
HE B VAR
HE B VAR
IPE 140
IPE 360
IPE 360
IPE 140
HE B VAR
HE B VAR
IPE 140
IPE 360
IPE 140
HE B VAR
6,00
X5
24,00
6,00
IPE 140
IPE 140
IPE 140
IPE 140
IPE 140
IPE 140
CBF
X4
6,00
IPE 140
IPE 140
IPE 140
IPE 140
IPE 140
IPE 140
X3
6,00
IPE 140
IPE 140
IPE 140
IPE 140
IPE 140
5 0
1
IPE 140
X2
X1
Y
Y1
Y2
Y3
Y4
Y5
Y6
X
Priestley and Kowalsky (2000)
MRF
CBF
November 14, 2006, DAPS, Naples, Italy
Displacement Based Design
High values of fundamental period (T>2.5 secs)
T INDIPENDENT
E.P.P.
⎛Δ⎞
⎜ ⎟ = 3%
h
⎝ ⎠ i ,u
r=0,05
r=0,10
r=0,15
r=0,20
0.0799
0.0799
0.0799
0.0799
0.0799
0.6734
0.6734
0.6734
0.6734
0.6734
8.42
8.42
8.42
8.42
8.42
(KN)
503.121
489.556
504.165
519.749
536.396
= (KN/m)
747.167
727.023
748.718
771.862
796.583
(m)
22.446
22.446
22.446
22.446
22.446
(ton)
864.62
864.62
864.62
864.62
864.62
17.67%
18.30%
17.63%
16.95%
16.27%
6.759
6.852
6.752
6.650
6.546
K
SDOFeq
heff
=
SDOFeq
SDOFeq
=
m
=
x SDOFequ
SDOFeq
T SDOFeq =
(s)
0.60
0.50
?
0.40
SDe(T) [m]
DySDOFequ (m)
DuSDOFequ (m)
mSDOFequ
FY
Elastic Displacement Response Spectrum, SDe(T)
BI-LINEAR
0.30
0.20
T DIPENDENT
E.P.P.
⎛Δ⎞
⎜ ⎟ = 3%
h
⎝ ⎠ i ,u
DySDOFequ (m)
DuSDOFequ (m)
mSDOFequ
r=0,05
r=0,10
r=0,15
r=0,20
0.0799
0.0799
0.0799
0.0799
0.0799
0.6734
0.6734
0.6734
0.6734
0.6734
8.42
8.42
8.42
8.42
(KN)
482.209
488.415
502.972
518.501
535.087
K SDOFeq = (KN/m)
FY
h eff
SDOFeq
=
=
m SDOFeq =
x SDOFequ
T SDOFeq =
0.00
0.00
1.00
2.00
3.00
4.00
5%
716.113
725.328
746.946
770.008
794.639
(m)
22.446
22.446
22.446
22.446
22.446
(ton)
864.62
864.62
864.62
864.62
864.62
18.66%
18.36%
17.68%
17.00%
16.32%
6.904
6.860
6.760
6.658
6.544
(s)
5.00
6.00
7.00
8.00
9.00
T[s]
8.42
SDOFeq
?
0.10
BI-LINEAR
ξeffective =
10%
15%
20%
⎞ 1
a ⎛
1 ⎞ ⎛
1
⎟⋅
⋅ ⎜⎜1 − b ⎟⎟ ⋅ ⎜⎜1 +
d ⎟
π ⎝ μ ⎠ ⎝ (Teffective + c ) ⎠ N
25%
28%
N = 1+
1
(0.5 + c )d
November 14, 2006, DAPS, Naples, Italy
10.00
Experimental Tests
Columns:
• Partially encased HEB 260 (external frames)
• Partially encased HEB 280 (internal frames)
HEB140
Foundation block layout: traditional connection
November 14, 2006, DAPS, Naples, Italy
Experimental Tests
•
Two partially encased columns with a steel HEB 260 member and
traditional connection to foundation (stiffening plates and
anchoring devices);
•
Two partially encased columns with a steel HEB 260 member and
innovative connection to foundation (socket-type foundation);
•
Two partially encased columns with a steel HEB 280 member and
innovative connection to foundation (socket-type foundation).
0,4 m
0,7 m
3,0 m
3,0 m
0,7 m
3,5 m
3,5 m
Specimen
7m
5m
0,4 m
HEB
HEB
HEB
HEB
HEB
HEB
260
260
260
260
280
280
Axial Load
N[kN]
330
170
330
330
520
520
Test
condit ion
Monot onic
Monot onic
Monot onic
Cyclic
Monot onic
Cyclic
Base column
Tradit ional (ISPRA)
Tradit ional (ISPRA)
Socket – Type
Socket – Type
Socket – Type
Socket – Type
November 14, 2006, DAPS, Naples, Italy
Experimental Tests
Traditional connection (HEB260)
Horizontal load (kN)
400
300
Base Column Yield
200
260-TMAX (N=330kN)
100
260-TMIN (N=170kN)
0
0,0
2,0
4,0
Drift (%)
November 14, 2006, DAPS, Naples, Italy
6,0
Experimental Tests
Socket type connection
8,00
D/H [%]
6,00
4,00
2,00
base - (0_6)
-6,00
-4,00
0,00
-2,00
0,00
2,00
4,00
-2,00
-4,00
-6,00
November 14, 2006, DAPS, Naples, Italy
6,00
[%]
8,00
Experimental Tests
Traditional vs. socket type-connection
N=330kN
600
Traditional base
600
400
Base moment (kNm)
Base moment (kNm)
500
Socket-type base
300
200
100
HEB 260
0
0,00
0,03
0,05
0,08
500
400
HEB 260
Socket-type base
300
200
HEB 280
Socket-type base
100
0,10
0
0.00
0.03
0.05
600
500
600
Traditional base
300
300
200
Socket-type base
150
100
-0,03
-0,02
-0,01
D /H [%]
0,01
0,02
-200
-300
-400
-500
HEB 260
0,03
-4,00
0
-2,00
0,00
-150
2,00
4,00
6,00
8,00
10,00
12,00
-300
-450
Test n°1 traditional connection
Test n°1 socket type connection
-600
Lateral Drift (rad)
M [kNm]
450
400
0
-100<0,00
0.10
Lateral Drift (rad)
Lateral Drift (rad)
Base moment (kNm)
0.08
-600
Test n°2 socket type connection
November 14, 2006, DAPS, Naples, Italy
0.13
Observations
•
Traditional base column joints employing welded steel end
plates cause large concentration of inelastic demand in the
anchorage bolts.
•
Anchors trigger bond type mechanisms that can exhibit limited
energy dissipation capacity.
The elongation of the bolts before fracture and the deformation
of the concrete beneath the rigid steel end plate give rise to a
significant increase of the lateral displacement at the column
top.
The innovative socket type joint was tested and improved
inelastic (monotonic & cyclic) response was observed.
Further experimental and numerical studies are needed to assess
the structural performance of socket type connections.
•
•
•
November 14, 2006, DAPS, Naples, Italy
Experimental Tests
Concrete filled composite columns
Traditional
25
31.5
219.1
10
45 40
10
30
70
550
50
60
150
50
G4
G3
550
150
Y
X
G1
219.1
10
G2
12
80
15
24
80
10
15
219.1
12
10
40
270
50
160
150
10
24
550
22
100
250
24
550
Bullone Ø24 passante
439.1
250
10
Socket
125
24
50
550
15
12
12
24
40
125
24
24
125
22
12
12
22
40
125
100
24
439.1
22
50
Dima di centraggio
November 14, 2006, DAPS, Naples, Italy
Experimental Tests
Simply supported beams (hogging moments)
A
Lamiera grecata tipo
A 55/P 600 HI-BOND
t = 1.5 mm Fe 430 h =55 mm
Calcestruzzo Rck 250
Rete elettrosaldata Ø10/25
55
150
150
55
150
P
95
95
95
90
95
Costolature (s=10mm) saldate Fe430
(saldatura a completa penetrazione)
360
Costolature (s=10mm) saldate Fe430
(saldatura a completa penetrazione)
IPE 360 (Fe 430)
2085
90
A
Hogging moment tests
90
90
90
5000
90
90
Total/Partial interaction
Lamiera grecata tipo
A 55/P 600 HI-BOND
t = 1.5 mm Fe 430 h =55 mm
To evaluate:
P
Sezione A-A
61,5
88,5
IPE 360
(i) Effective width;
(ii ) Interaction (degree);
(iii) Cyclic loading.
55
250
12,7
1000
150
150
8
R1
8
360
334,6
90
Costolature (s=10mm) saldate Fe430
Solaio composto
calcestruzzo-lamiera grecata
Rete elettrosaldata Ø10/25
55
150
12,7
170
Beam span L=4.0m (IPE 360)
November 14, 2006, DAPS, Naples, Italy
Experimental Tests
W/C = 0.50
HEB 180 – S275
25
Load - Slip
Load [KN]
20
15
10
5
0
0
5
10
15
20
25
Slip
November 14, 2006, DAPS, Naples, Italy
Numerical Simulations
Evaluation of deformations
Slip
Traditional
Φ= Slip/(H-x)
B
c
H
A's
ε's
φy
εc
xc
M
N
c
As
Socket
εbolt
Fixed end rotation
November 14, 2006, DAPS, Naples, Italy
Final Remarks
•
Deformation capacity of steel & concrete composite beams
should be further investigated particularly under hogging
moments.
•
Ductility/Energy dissipation capacity of beam-to-column and
base column connections should be analysed both
experimentally and numerically for traditional and innovative
layouts.
•
Refined analytical models able to predict reliable inelastic
response of composite members are still lacking.
•
Adequate limit states (local & global) should be defined to
assess reliably the seismic response of composite framed
structures, especially with the framework of displacementbased design.
November 14, 2006, DAPS, Naples, Italy