PSI - Issue 44

Sabatino Di Benedetto et al. / Procedia Structural Integrity 44 (2023) 1901–1908 Di Benedetto et al. / Structural Integrity Procedia 00 (2022) 000 – 000

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2.40 m. Each MRF can be considered extracted from a more complex reference structure characterized by three bays in each direction (Fig. 1b), with lengths equal to 4.00 m. Four MRFs characterize the reference building in each direction, while the remaining bays are nominally pinned (Fig. 1c). The loads and masses applied to the structure are summarized in Table 1. The masses have been evaluated considering the tributary area of each MRF equal to 1/4 of the total area of the deck, with a 10% increase accounting for the weight of structural members and claddings. The structural members have been designed to comply with the Eurocode 8 provisions (EN1998-3, 2005), considering the Ductility Class High, q=6.00, soil type B and PGA=0.35g. In particular, the design interstorey drifts under service conditions have been limited to 1% since the partition walls of the building are supposed not to interfere with the deformation of the main structure. According to the previous statements, the design procedure selected IPE 270 and HEB 200 profiles for the beams and the columns, respectively. The beams are made of S275JR steel grade, while the columns are characterized by S355JR steel grade.

a) Lateral view of the mock-up (MRF RBS)

b) 3D view of the reference scheme

c) Plan view

Fig. 1. Building mock-up (a) and its reference structure (b-c)

Table 1. Dead loads and masses First level

Second level

Dead load (kN/m2) Live load (kN/m2)

3.90 3.00

3.60 0.50

Mass (tons) for one frame

19.00

14.20

The building mock-up was equipped with RBS connections during the first experimental campaign. RBSs have been designed assuming a flange width reduction equal to 25%, according to FEMA 351 (2000), for a flange reduction equal to 22 mm (Fig. 2). Instead, and have been assessed according to Eqs. (1-2): = , ℎ , , = 100.82 (1) = , 2 − − − /2 = 71.21 (2) where , is the plastic modulus of the RBS, , ℎ is the overstrength factor, , is the value of the yield strength of the RBS for S275JR steel grade, , is the beam net length, is the end-plate thickness, and are geometrical parameters that control the length and position of the RBS, defined according to Moore and Malley (1999) and shown in Fig. 2. Starting from the knowledge of the previous actions, all the other nodal components have adequately been designed according to the component method approach.