Issue 62

D. Wang, Frattura ed Integrità Strutturale, 62 (2022) 364-384; DOI: 10.3221/IGF-ESIS.62.26

Figure 19: IP-OOP indicator profiles of infill wall.

As can be seen from Figs. 18 and 19, the IP indicator profiles presented a ">" shape, and the IP infill walls had large in plane deformations at the 2nd and 3rd storeys. The IP infill walls reached or exceeded DS1 and DS2 damage states for the PGA of 0.1g and 0.2g, respectively. At the upper storeys of the structure, the IP indicator values were relatively small, and the infill walls suffered less damage. The vertical variation trend of the IP-OOP indicator showed a "W" shape, and the IP-OOP indicator values were relatively large at the 2nd to 4th storeys of the structure. The IP-OOP infill walls reached or exceeded DS2 and DS3 damage states for the PGA of 0.1g and 0.4g, respectively. Compared with the IP indicator response, the IP-OOP indicator increased significantly at the 4th storey of the structure. It is clearly necessary to consider the IP-OOP interactions of the infill walls under seismic actions, as the increasing OOP suppresses infill wall stiffness. The IP damages of infill walls are proportional to the interlayer displacement angle of the structure, and negatively correlated with the height of the structure. However, the OOP actions on the equivalent elements are proportional to the inertia forces of the infill walls, which generally increase with the height of the structure. Therefore, the effects of IP-OOP interactions on the vulnerability of infill walls can be maximized on the mid-storeys of the structure, and may cause damage to the infill walls in these storeys. IDA and vulnerability curves of RC frame with infill wall. Taking the maximum interlayer displacement angle as the abscissa, and the PGA as the ordinate, the IDA curves, as well as the IDA curves of the 16%, 50%, and 84% quantiles, were plotted for the frame with IP-OOP infill wall, and the frame with IP infill wall (Figs. 20 and 21).

1

1

0.8

0.8

0.6

0.6

PGA (g)

PGA (g)

0.4

0.4

50% quantile

50% quantile

0.2

84% quantile

0.2

84% quantile

16% quantile

16% quantile

0

0

0

0.01

0.02

0.03

0.04

0.05

0

0.01

0.02

0.03

0.04

0.05

θ max

θ max

Figure 20: IDA curves of the frame with IP-OOP infill wall.

Figure 21: IDA curves of the frame with IP infill wall.

The IDA results show that: for the frame with IP-OOP infill wall, when the PGA was less than 0.3g, the discreteness of the IDA curves was small, the maximum interlayer displacement angle almost changed linearly, and the structure belonged to the elastic stage. When the PGA was greater than 0.3g, the discreteness of the IDA curves gradually increased with a clear nonlinearity, and the structure entered the elastic-plastic stage. Under a rare earthquake ( PGA =400 gal ), the median of

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