PSI - Issue 64

Massimiliano Ferraioli et al. / Procedia Structural Integrity 64 (2024) 1025–1032 Ferraioli et al./ Structural Integrity Procedia 00 (2019) 000–000

1030

6

t ) and stiffness ( K y

t ), clear length ( b

p ), height ( h p ) thickness ( t ), number of strips

Table 6. Properties of SSDs in X-Direction. (Target strength ( Q p

( n s ) to be used in each steel slit damper are calculated to reproduce the required stiffness and strength X-Direction – EBFs on the Long Side Y-Direction – EBFs on the Short Side N. Q p t [kN] K y t [kN/mm] b p [mm] h p [mm] t [mm] b p1 [mm] h p1 [mm] n S Q p t [kN] K y t [kN/mm] b p [mm] h p [mm] t [mm] b p1 [mm] h p1 [mm] n S 1 155.6 390 65.0 25 97.5 32.5 396.0 14 259.9 103.7 390 65.0 23 97.5 32.5 10 2 124.7 390 65.0 25 97.5 32.5 311.2 11 210.6 83.13 390 65.0 23 97.5 32.5 8 3 69.83 390 65.0 25 97.5 32.5 169.7 6 118.0 46.56 390 65.0 17 97.5 32.5 4

Table 7. Properties of SSDs in Y-Direction.

N. Q p t

K y t [kN/mm]

h p [mm]

t [mm]

b p1 [mm]

h p1 [mm]

Q p [kN]

b p [mm]

n s

[kN]

1 322.3 87.13 2 261.2 69.84 3 146.3 57.74

580 96.67 23 580 96.67 19 390 65.0 15

145 48.33 309.6 8 145 48.33 255.8 8 97.5 32.5 135.8 8

a)

b) Fig. 8. a) Layout in plan of EBFs in parallel exoskeleton; b) Layout in plan of CBFs in orthogonal exoskeleton.

4. Seismic assessment The seismic evaluation employs nonlinear time-history analysis, which incorporates two simultaneous accelerograms, each representing a horizontal earthquake ground motion component. Real-ground motions are selected and scaled according to spectrum-compatibility rules. Fig. 9 illustrates the target and average spectrum, alongside scaling factors ensuring spectrum compatibility. Fig. 10 depicts the variation in peak Inter-story Drift Ratio (IDR) response across the building height for the CP Limit State, in X and Y directions for two columns (A and D). In the X-direction, the IDR response distribution is more uniform compared to the Y-direction, where the highest IDR response occurs at the 1st and 2nd stories. The IDR response varies slightly in the X-direction due to torsional effects. The peak IDR response remains below the transient drift limit of 2%, aligning with the collapse prevention objective.

Epicentral Distance [km]

EQ. ID

Earthquake Name

a g (X) [m/s 2 ]

a g (Y) [m/s 2 ]

N.

Date

M w

E1 133 Friuli

15/09/1976 6.0

9

1.069 0.932 1.685 1.041 3.814 5.027 2.354 2.670 2.108 3.000 3.699 5.036 2.838 1.671

E2 600 Umbria Marche 26/09/1997 6.0

22 13 11 10

E3 535 Erzincan E4 414 Kalamata E5 413 Kalamata E6 1703 Duzce 1 E7 334 Alkion

13/03/1992 6.6 13/09/1986 5.9 13/09/1986 5.9 12/11/1999 7.2 24/02/1981 6.6

8

19

Fig. 9. Selected earthquake records and their spectrum compatibility.