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1Sixth NEES Annual Conference, 2008, Portland, Oregon
Preliminary Analytical Studies on Composite Shear Wall Systems
Presented by:
Dr. Qiuhong Zhao
Assistant Professor, Dept. of Civil and Env. Engineering University of Tennessee, Knoxville
2Sixth NEES Annual Conference, 2008, Portland, Oregon
Components of Composite Wall System
Steel Plate Wall
Steel Columns and Beams
PrecastConcreteWall
Bolts
Specimen One (Innovative System)
Gap
Specimen Two (Traditional System)
No Gap
Composite Shear Wall Systems Studied(Innovative System Developed at UC Berkeley by A. Astaneh and Q.Zhao)
3Sixth NEES Annual Conference, 2008, Portland, Oregon
“Gap”
Control Mechanism
Proposed Innovative Traditional
GAP in Concrete
only
4Sixth NEES Annual Conference, 2008, Portland, Oregon
FEM Analyses
on Test
Specimens
Contact Surface
Bolts in Specimen
1¼
inch gap
NSF1 Model
Negligible Gap
NSF2 Model Specimen Model
All components: 2-D Shell Elements
Bolts: 1-D Beam Elements with released rotation DOF
5Sixth NEES Annual Conference, 2008, Portland, Oregon
Specimen
One
NSF1-
Steel Parts NSF1 –
RC Wall
6Sixth NEES Annual Conference, 2008, Portland, Oregon
Specimen
Two
NSF2 –
Steel Parts NSF2 –
RC Wall
7Sixth NEES Annual Conference, 2008, Portland, Oregon
Parametric Study ( A572 Gr. 50 Steel Wall )
Effects of Steel Wall Material Strength - NSF1
0
100
200
300
400
500
600
700
800
0 1 2 3 4 5 6 7 8 9 10 11 12Overall Lateral Displacement (inch)
Shea
r For
ce (k
ip)
Specimen one ( A36 steel wall)
Specimen one with A572 Gr. 50 steel wall
NSF1 vs NSF2 with A572 Gr. 50 Steel Wall
0
100
200
300
400
500
600
700
800
0 1 2 3 4 5 6 7 8 9 10 11 12
Overall Lateral Displacement (inch)
Shea
r For
ce (k
ip)
NSF1_mod
NSF2_mod
NSF1_mod NSF2_mod
8Sixth NEES Annual Conference, 2008, Portland, Oregon
Parametric Study ( 8ksi Concrete )Effects of RC Wall Material Strength - NSF1
0
100
200
300
400
500
600
700
800
0 1 2 3 4 5 6 7 8 9 10 11 12Overall Lateral Displacement (inch)
Shea
r For
ce (k
ip)
Specimen one
Specimen one with 8ksi concrete
NSF1 vs NSF2 with f'c=8ksi
0
100
200
300
400
500
600
700
800
0 1 2 3 4 5 6 7 8 9 10 11 12
Overall Lateral Displacement (inch)
Shea
r For
ce (k
ip)
NSF1_mod
NSF2_mod NSF1_modNSF2_mod
9Sixth NEES Annual Conference, 2008, Portland, Oregon
Parametric Study ( Double Wall Thickness )Effects of Steel Wall Thickness - NSF1
0
100
200
300
400
500
600
700
800
900
0 1 2 3 4 5 6 7 8 9 10 11 12Overall Lateral Displacement (inch)
Shea
r For
ce (k
ip)
Specimen one
Specimen one with doubled steel wall thickness
NSF1 vs NSF2 with 3/8" Steel Wall Thickness
0
100
200
300
400
500
600
700
800
900
0 1 2 3 4 5 6 7 8 9 10 11 12
Overall Lateral Displacement (inch)
Shea
r For
ce (k
ip)
NSF1_mod
NSF2_modNSF2_modNSF1_mod
10Sixth NEES Annual Conference, 2008, Portland, Oregon
Summary from Preliminary Analyses
Finite element analyses were able to predict the major behavioral characteristics of the specimens observed during the experimental studies.
Parametric studies showed that the steel wall is the major component of the systems investigated, and its stiffness and strength have a major contribution to the overall system stiffness and strength.
Using A572 Gr. 50 steel wall would be an effective way to strengthen the systems investigated.
Increasing the steel wall thickness would be a very effective way to strengthen the system investigated. However, premature failure of the system might occur if column is not strong enough.
Using higher strength concrete for the RC wall would not be an effective way to strengthen the systems investigated.
A “balanced” design principle is suggested for the structural components of the systems investigated, which would emphasize strong column, weak wall design to avoid premature failure of the system due to failure of the column.
11Sixth NEES Annual Conference, 2008, Portland, Oregon
Thank you………. Questions?
