PSI - Issue 78

Ahmed Mabrouk et al. / Procedia Structural Integrity 78 (2026) 960–967

963

Fig. 2. Experimental and numerical results: cyclic IP (left), and monotonic OOP (right) response

4. Assessment of infill macro-model through non-linear TH analysis 4.1. Presentation of case study frame

The case study investigates the seismic performance of a 2D RC frame model (see Fig. 3a), representative of a frame building constructed in Italy between 1960s-1980s, therefore designed for gravitational loads only. The structure is an eight-storey, three-bay residential frame, with regular geometry in both plan and elevation. For information regarding the section details, please refer to Minotto (2019). Three configurations of the frame are analyzed BF – Bare frame without infill walls, URM – Infilled with unreinforced masonry panels (hollow clay units), F – Infilled with strengthened panels using a fiber-reinforced plaster (F) system. Beams and columns are modeled using the force-based fiber section formulation described in section 2. All three frame variants share the same geometry, boundary conditions, and gravity loads, ensuring that differences in structural response can be directly attributed to the presence and type of infill. Infill panels are assigned the calibrated properties from section 3 and are present in all bays and storeys. For the TH Analysis, 7 bidirectional natural records were chosen from the SIMBAD Database. These records were scaled to be compatible (on average) with the Type 1 elastic response spectrum of EC8, considering a bedrock acceleration (ag) of 0.25 g and a soil type B, which results in a peak ground acceleration of 0.3 g. The main details of these accelerograms are reported in Table 2, and the associated acceleration spectra are shown in Fig. 3b together with the EC8 reference spectrum.

Table 2. Selected bidirectional natural records

Epicentral Distance Scale Factor [km] X Y

ID Earthquake

Date

Acc. 1 Eastern Fukushima Prefecture 2011/04/11 6.5

26.24 24.68 25.38 21.72 27.56 21.79 18.85

1.30 1.59 0.60 0.79 2.33 1.34 1.43

1.38 1.48 0.97 0.72 1.41 1.93 1.58

Acc. 2 Imperial Valley Acc. 3 S. Suruga Bay Acc. 4 Friuli 1 st shock

1979/10/15 6.5 2009/08/10 6.2 1976/05/06 6.4 1980/11/23 6.9 1980/11/23 6.9

Acc. 5 Eastern Fukushima Prefecture 2011/04/11 6.6

Acc. 6 Irpinia Acc. 7 Irpinia