Issue 69

A. Almeida et alii, Frattura ed Integrità Strutturale, 69 (2024) 89-105; DOI: 10.3221/IGF-ESIS.69.07

Vibration control through semi-active MR dampers In order to obtain the Optimized Controlled configuration (C3), 35 MR dampers are applied to the central frames of the Optimized Uncontrolled structure (C2), one per floor. Each floor is controlled by the damping force MR F m , with   1 35 m to  , as illustrated in Fig. 6.

Figure 6: Position of the dampers.

In the LQR solution, the following weight matrices are considered, as indicated by [62]:

K

0 0



   

  , n n

 10 d m m R I   7 ,

 

and

(22)

Q



0

 

  , n n

  , n n

Dynamic wind load The dynamic wind load is modeled according to the procedures presented previously. Tab. 3 presents a summary of the parameters used, in which 3 S is adopted considering the Serviceability Limit State, with a recurrence time of 10 years.

Parameter

Unity

Value

-

1.45

D C

m²

10.69

i A

m/s

43

0 V

- - - -

1

1 S 3 S

0.78

b p

1

0.15

Hz

i f

5 10 ~10 

-

0.4

* k

m m m

10

ref z

0.07

o z

* L 1200 Table 3: Parameters used to determine the wind load. Fig. 7 shows the drag force at floor 01 (first), floor 20 (approximately half the height of the frame), and floor 35 (last floor).

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