PSI - Issue 44

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Alessandro Mei et al. / Procedia Structural Integrity 44 (2023) 2318–2325 Mei, et al./ Structural Integrity Procedi 00 (2022) 000– 00

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Figure 6. (a) q- factor obtained for experimental ductility. (b) The ratio between the q -factor obtained using a pinching constitutive law and the value recommended by IBC. 5. Concluding remarks This study aimed to investigate if and how the reduced hysteresis loops typical of the pinching behavior affect the force-reduction factor. The main results can be summarized as follows: • Racks, due to their connections, have a peculiar cyclic response that cannot be compared to the elastic plastic behavior that better describes ordinary steel and reinforced concrete buildings; • When performing nonlinear static analysis, the displacement demand is currently obtained by considering classical elastic-plastic hysteresis (as done by IBC and E.C.); however, we have shown that the displacement demand in the presence of pinching can be significantly higher, especially for the typical values of rack fundamental periods between 1 and 2 seconds; • Consequently, when using linear analyses, evaluating the q factor by ductility only, without accounting for the different dynamic seismic responses can lead to a significant overestimation of the force reduction factor itself. Aguirre, C. (2005). Seismic behavior of rack structures. Journal of Constructional Steel Research, 61(5), 607–624. https://doi.org/10.1016/j.jcsr.2004.10.001 Avgerinou, S., Lignos, X., Tsarpalis, D., & Vayas, I. (2019). Full-scale tests on used steel storage racks. Steel Construction, 12(3), 231–242. https://doi.org/10.1002/stco.201900009 Bernuzzi, C., & Castiglioni, C. A. (2001). Experimental analysis on the cyclic behavior of beam-to-column joints in steel storage pallet racks. Thin-Walled Structures, 39(10), 841–859. https://doi.org/10.1016/S0263-8231(01)00034-9 Bernuzzi, C., di Gioia, A., Gabbianelli, G., & Simoncelli, M. (2017). Pushover Analyses of Hand-Loaded Steel Storage Shelving Racks. Journal of Earthquake Engineering, 21(8), 1256–1282. https://doi.org/10.1080/13632469.2016.1210063 Bertocci, L., Comparini, D., Lavacchini, G., Orlando, M., Salvatori, L., & Spinelli, P. (2017). Experimental, numerical, and regulatory P-Mx-My domains for cold-formed perforated steel uprights of pallet-racks. Thin-Walled Structures, 119, 151–165. https://doi.org/10.1016/j.tws.2017.06.001 C. S. LL. PP. (2018). Aggiornamento delle Norme Tecniche per le Costruzioni - D.M. 17/01/2018. Castiglioni, C. A. (2016). Seismic Behavior of Steel Storage Pallet Racking Systems. CEN European Committee for Standardization. (2009). EN 15512, Steel Static Storage Systems - Adjustable Pallet Racking Systems - Principles for Structural Design. CEN European Committee for Standardization. (2016). EN 16681, Steel static storage systems - Adjustable pallet racking systems - Principles for seismic design. Comparini, D., Bertocci, L., Salvatori, L., Orlando, M., Lavacchini, G., & Spinelli, P. (2017). Down-Aisle Seismic Behavior of Pallet-Rack Systems : Experimental Tests and Numerical Analyses. XVII Convegno ANIDIS - L’Ingegneria Sismica in Italia, 72–81. Dai, L., Zhao, X., & Rasmussen, K. J. R. (2018). Cyclic performance of steel storage rack beam-to-upright bolted connections. Journal of Constructional Steel Research, 148, 28–48. https://doi.org/10.1016/j.jcsr.2018.04.012 References