Optimum Design of a New Hysteretic Dissipater - Design Optimization of Active and Passive Structural Control Systems - page 285

Figure 7. Details of the construction of the aluminum-steel device corresponding to 20 kN transversal
load: the device has 12 openings (n x =3 in horizontal and n y =4 in vertical) and b 1 =8 mm, b 2 =40 mm,
b 3 =8 mm, h 1 =10 mm, h 2 =100 mm, h 3 =10 mm, t 1 =1 mm, t 2 =3 mm, t a =3 mm.

Extension of the Optimum Design to
Devices with Different Shear Loads

column is identified by a name that represents the
best solution obtained using the maximum shear
load reported in the column headers. It may be
noted that this name identifies an average range
of the transverse load that can ensure a proper use
of the panel. For a relatively low increase in the
shear load, the best solution is achieved mainly
by changing the thickness and the dimensions
of the window of the aluminum panel. Instead,
the solution obtained for a shear load of 100 kN
differs significantly, since the aluminum window
is almost doubled in width. In other words, the
increase of the amount of transversal load initially
produces a moderate increase and then a higher
increase of the panel width.
Once the optimization procedure has been used
to determine more geometrical configurations of
the panels, their behavior has been numerically
evaluated: it consists essentially of the link be-
tween the top displacement and the applied shear
load. Again, the models include the nonlinear

The same procedure was then extended to differ-
ent geometrical configurations of the shear panel
simply by changing a particular design parameter,
the constraint of the maximum transverse load.
Since an effective dissipation can be obtained only
if panel and structure stiffness are comparable, it
is possible to define a series of panels, designed to
protect frames that have different structural stiff-
ness. This objective was achieved by changing the
maximum shear force and keeping unchanged the
other parameters and constraints. In this way, the
optimization procedure automatically selects the
best solution for each class of the shear load. The
farther design cases considered are those related
to load values of 40 kN, 80 kN and 100 kN. The
results obtained for the optimal configuration are
presented in Table 3, while in Figure 8 the details of
construction of the 40 kN panel are reported. Each