PSI - Issue 25

L. Martelli et al. / Procedia Structural Integrity 25 (2020) 294–304 Lucrezia Martelli/ Structural Integrity Procedia 00 (2019) 000–000

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structure, the existing one forming part of the coupled system and the only exoskeleton structure have been split in order to clearly understand the effectiveness of the investigated solution, as reported also in Figure 8. Table 4. Stiffness of the primary structure ( ���� ) and the coupled system ( ���� ) for two seismic combinations and their stiffness ratio

Primary structure

Coupled system

Ratio ���� / ���� [-]

24514 16453 ���� [t/m]

[t/m] ����

Direction � � ���� � � � � ���� � �

171919 112320

7.01 6.83

Table 5. Peak shear forces ( � , � ) for the primary structure and the coupled system in x- and y-direction, LLS

Primary structure � �

[kN] � � Coupled system

Level

[kN]

[kN]

[kN]

1 2 3 4

6428.80 5676.70 4189.70 1913.50

6114.20 5378.30 4078.50 1980.60

12841.50 11776.60 8962.80 4593.50

11915.10 11009.70 8861.10 4808.60

Table 6. Base shear forces ( � ) for the existing structure and the primary-exoskeleton components of the coupled system in x- and y-direction, LLS

Primary structure

Coupled system

x-dir y-dir � � ��

Total

Primary Exoskeleton

Total

6428.80 6114.20

6428.80 6114.20

1729.00 1655.00

11112.50 10260.10

12841.50 11915.10

C, primary C, exoskeleton U, primary

y-dir x-dir

0 2000 4000 6000 8000 10000 12000 Base shear force [kN]

Fig. 8. Comparison between base shear forces of the existing structure and the primary-exoskeleton components of the coupled system in x- and y-direction, LLS