GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 2.2 GNGTS 2024 Where F is the applied load, B and H are the floor dimensions parallel and orthogonal to the orientaCon of the beams respecCvely, and d 1 and d 2 are the length variaCon of the diagonals. Values of the equivalent sCffness are shown in Table 1. A first shear sCffness G 0-30 was calculated between 0% and 30% of the maximum shear load carried by the sample, while a second value (G 10-40 ) between 10% and 40% of the maximum load, in accordance to UNI- EN12512 (2006). Two non-reinforced floors (TF-UR-G and TF-UR-NG) were selected for the analyses: the first with gaps between the planks and the second without gaps. Their difference is emphasized by the G 0-30 sCffness, which is eighteen Cmes higher for the NG case, where the fricCon between the parts of the floor plays an important role. The influence of the iniCal sCffness is parCally lost when evaluaCng G 10-40 . Three types of reinforced floors were considered. TF-OSB-N and TF-OSB-S were sCffened with 25 mm thick OSB panels and ringed- nails (N case) or screws (S case). On the other hand, TF-CLT-S floor was reinforced with 60 mm thick CLT panels, which were fastened with screws. Each floor was modelled as an equivalent shell element with an elasCc behaviour. Furthermore, the case of rigid diaphragm was also taken into account (TF-RIGID). Table 1 – Timber floor typologies considered for the non-linear analysis of the case study Villa, as derived from the experimental invesCgaCons in (Gubana and Melobo 2021b) Results The parametric numerical results were analysed in term of displacements. A comparison between base shear and top displacement obtained for each configuraCon of Table 1 was also carried out. Pushover analyses were performed in the North-South direcCon (Y direcCon according to Fig. 2), which corresponds to the orientaCon of Cmber joists. In accordance with the Italian Building Code, a mass proporConal (Group 1) and an acceleraCon proporConal (Group 2) configuraCon were considered for loading. ID Features Reinforcement type Connectors G 0-30 [kN/mm] G 10-40 [kN/mm] TF-UR-G With gaps - - 0.09 0.06 TF-UR-NG No gaps - - 1.66 0.65 TF-OSB-N OSB panel Ringed-Nails 19.52 5.92 TF-OSB-S OSB panel Self-tapping screws 10.49 3.81 TF-CLT-S CLT panel Self-tapping screws 5.69 2.83 TF-RIGID - - - -