Civil Engineering Reference
In-Depth Information
90
80
70
60
50
40
30
20
10
0
0
0.2
0.4
0.6
0.8
1
e/D
FIGURE 7.7
The relationship between the normalized compression zone size and eccen-
tricity in circular columns. (Courtesy of Abd El Fattah [2012].)
ε
cu
to construct a Lam and Teng eccentric curve. The strain ε
cu
is found by linear
interpolation between the two extreme bounds of strain, as seen in Figure 7.8:
ε=
−
−
f
f
cc
c
(
)
ε− +
0.003
0.003
(7.48)
cu
ccu
f
f
cc
c
Any point on the generated eccentric curves can be calculated using the follow-
ing equations:
(
)
2
EE
f
−
c
2
2
f
=ε−
E
ε
for0
≤ ε≤ε
(7.49)
c
c
c
c
c
t
4
c
f
=+ε
f
E
for
ε ≤ε ≤ε
(7. 50)
c
c
2
c
t
c
cu
f´
cc
f
cc
f´
c
ε
´
c
ε
t
0.003
ε
cu
ε
ccu
Axial Strain
FIGURE 7.8
Eccentricity-based confined Lam and Teng model.
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