Geology Reference
In-Depth Information
Table 3. Optimal values of the geometrical pa-
rameters for different service loads
to this condition could be higher than 4 mm, which
is the maximum acceptable interstory drift of the
structure to be protected. Figures 10, 11, 12, and
13 report the map of the plastic deformation and
the first mode of instability for each of the panels
examined. The first mode of instability is shown
in the mentioned figures and it occurs for 3.928
mm, 3.532 mm, 5.328 mm, 3.208 mm, respec-
tively, for panels of 20 kN, 40 kN, 80 kN and 100
kN. These values, especially for 40 kN and 100
kN devices, are lower than the design value of 4
mm, but they can be considered sufficiently close
to the limit value in order to assure a correct be-
havior of the panel.
Summarizing, it is possible to propose a design
procedure for this new aluminum-steel dissipater
in the range of shear forces 0-150 kN. At design
of the structure, the technician must choose the
most appropriate panel to be included in the
structure. The choice must be made based on the
shear force expected for the panel, once it is in-
serted into the structure. Therefore, the size of the
force must be assessed by a numerical model of
a structure without dissipaters but equipped with
the same braces that will be utilized to install the
devices.
The methodology to perform a proper evalu-
ation of this force and, consequently, the correct
selection of the panel to install, is as follows:
20
kN
40 kN
80 kN
100
kN
Geometrical Parameters
[10-
20
kN]
[20-40
kN]
[40-80
kN]
[80-
150
kN]
n
x
Horizontal windows
3
3
3
3
n
y
Vertical windows
4
4
4
4
Width of the lateral
steel reinforcing
[mm]
b
1
8
8
12
15
Width of the alumi-
num window[mm]
b
2
40
60
70
180
Width of the internal
steel reinforcing
[mm]
b
3
8
8
12
15
Height of the
external steel
reinforcing [mm]
h
1
10
10
15
10
Height of the alumi-
num window [mm]
h
2
100
100
95
100
Height of the
internal steel
reinforcing[mm]
h
3
10
10
15
10
Thickness of the
steel plate [mm]
t
1
1
4
3
4
Thickness of
the aluminum
plate[mm]
t
2
3
1
3
2
Projection of the
aluminum plate
[mm]
t
a
3
3
3
2
1. Definition of a simplified model of the
structure where the diagonal braces will be
modified to connect directly the end to the
structure, that is removing the panel itself.
2. Perform a seismic analysis of the simplified
model and evaluating the maximum shear
force that is generated at the point where the
panel will be added to the structure.
3. Select the device for which the previously
determined shear force will be within the
operational range of the panel.
behavior of the materials in order to determine
the behavior of the panel during yielding. The
characteristic curves obtained are reported and
compared in Figure 9.
Subsequently, a buckling analysis was per-
formed on each panel class in order to determine
the conditions corresponding to the possibility of
instability. The beginning of instability phenom-
ena leads to a quick panel stiffness reduction and
it represents a limiting condition for the real uti-
lization of the device. It would be desirable that
the transversal top displacement corresponding
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