PSI - Issue 44

Devis Sonda et al. / Procedia Structural Integrity 44 (2023) 1188–1195 Devis Sonda et al. / Structural Integrity Procedia 00 (2022) 000 – 000

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Fig. 8. C-SC30-FA mean values of 7 TH compared to linear simplified approach: column base (a) shear and (b) moment.

The curves highlight the good approximation between TH analyses and the proposed simplified approach based on linear analyses in quantifying the values of column base shear and moment. In the first elastic range, the black dashed curve (linear modal analysis) matches well the red one (TH analysis). In the second linear range, the increase in force values respect to F eq of the device is assumed to be totally due to column dynamic behavior, until reaching the SF value at maximum deformation value of the device. A wider range of numerical analyses must be performed in the future on different structural models in order to validate the procedure. 6. Conclusions The dissipative fuse Sismocell devices are used to provide effective connections between beam and columns in existing precast RC buildings. The device provides an amount of dissipation of energy to the structure and after reaching the end stroke in compression it works as a hinge that allow relative displacement between structural elements, avoiding loss of support and collapses. This specific behavior requires a non-linear modeling of the device to be considered properly in a structural analysis. The non-linear models, performed on frames with columns with linear elastic behavior, have highlighted the effect of CWST Sismocell devices in limiting the force transferred from the roof to the columns and consequently in reducing moment at column base. The percentage of reduction of effects of action is in the range from 30% to 69% for the models analyzed (excluding the model equipped with SC50 devices). The reduction of effects of action depends on different parameters, such as the seismic input and the equivalent plastic force threshold F eq . The analyses performed have shown that the devices are efficient to mitigate seismic peak values and the results can be used to define the optimal F eq to use for the specific structure and seismic input. A comparison between TH analyses and the proposed simplified approach based on linear analyses has shown a good approximation between results of the curves obtained from the two different types of analysis on the same model. The results of this analyses confirmed the effectiveness of the CWST Sismocell devices as a system able to improve the seismic behavior of friction-based connections of existing precast RC buildings. References M. Savoia, M., Buratti, N., Vincenzi, L., 2017. Damage and collapses in industrial precast buildings after the 2012 Emilia earthquake. Engineering Structures, 137, pp. 162-180. Bournas, D.A., Negro, P., Taucer, F.F., 2013. Performance of industrial buildings during the Emilia earthquakes in Northern Italy and recommendations for their strengthening. Bulletin of Earthquake Engineering, 12, pp. 2383-2404. Liberatore, L., Sorrentino, L., Liberatore, D., Decanini, L.D., 2013. Failure of industrial structures induced by the Emilia (Italy) 2012 earthquakes. Engineering Failure Analysis, 34, pp. 629-647. Pollini, A.V., Buratti, N., Mazzotti, C., 2018. Experimental and numerical behaviour of dissipative devices based on carbon-wrapped steel tubes for the retrofitting of existing precast RC structures. Earthquake Engineering & Structural Dynamics, pp. 1-21. Pollini, A.V., Buratti, N., Mazzotti, C., 2021. Behavior factor of concrete portal frames with dissipative devices based on carbon-wrapped steel tubes. Bulletin of Earthquake Engineering, 19, pp. 553-578. Sgobba, S., Puglia, R., Pacor F., Luzi, L., Russo, E., Felicetta, C., Lanzano, G., D'Amico, M., Baraschino, R., Baltzopoulos, G., Iervolino, I., 2019. REXELweb: a tool for selection of ground-motion records from the Engineering Strong Motion database (ESM). 7th International Conference on Earthquake Geotechnical Engineering (ICEGE) 17 - 20 June 2019, Roma, Italy