Civil Engineering Reference
In-Depth Information
where
k
d
denotes the initial stiffness of metallic damper,
α
denotes the second stiffness
coefficient and
x
y
is the yielding displacement. Figure 9.2 show force-displacement relations
of these two dampers.
9.1.2 Model of Framed Structures with PEDDs
To dissipate a great deal of input earthquake energy, the PEDD is usually connected with braces
or diagonal bars in series. In the FAM, assume that the force offered by the PEDD is distributed
on the joints of the frame and ignore the axial deformation of the bar, as shown in Figure 9.3 and
Figure 9.4 (Li and Li, 2011a), respectively.
When the PEDD is mounted eccentrically on the joint of chevron brace, the horizontal force
generated by the PEDD can be transmitted at the support joints as the horizontal restoring
forces, as illustrated in Figure 9.5 and is satisfied by
F
d
,
A
=
F
d
b
F
d
,
B
=
F
d
a
L
L
;
ð9
:
5Þ
(a)
(b)
F
d
F
d
F
y
F
y
α
k
d
x
y
x
x
Figure 9.2
Force-displacement relations of: (a) friction damper; (b) metallic yielding damper.
Reproduced with permission from John Wiley and Sons, (License No. 3132491366031).
(a)
(b)
(c)
P
F
d
P
F
d
Figure 9.3
Model of a diagonal brace equipped with a PEDD (
F
d
is the horizontal force generated by
PEDD;
P
is the axial force of diagonal brace): (a) diagonal brace model; (b) simplified axial force;
(c) simplified horizontal force. Reproduced with permission from John Wiley and Sons, (License No.
3132491366031).
