PSI - Issue 44

Elisabetta Maria Ruggeri et al. / Procedia Structural Integrity 44 (2023) 464–471 E. Ruggeri, G. D’Arenzo, D. Li Cavoli, R. Cottonaro, M. Fossetti/Structural Integrity Procedia 00 (2022) 000–000

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Fig. 6. Load-displacement curves obtained from monotonic tests.

Figure 8 (a) and (b) depict the hysteresis loops and the backbone curves, respectively. Both figures show the typical symmetrical hysteresis loops for positive and negative displacements of the SW configuration. On the other hand, for the SW+PW configuration, asymmetric hysteresis loops describe a different behavior of the system for positive and negative displacements. This asymmetric behavior is due to asymmetric distribution of the anchoring system. In fact, while the connections at the base of the shear wall are symmetrically distributed, the perpendicular wall, which is connected only to one side of the shear wall, makes the overall anchoring system asymmetric and with it the shear wall lateral response. Maximum load values of 49.54 and 32.01 kN were obtained in case of positive and negative displacements, respectively, see Figure 8. This asymmetry, visible in the hysteresis loops and in the backbone curve, is further confirmation that the perpendicular wall influences the lateral behavior of the shear wall subjected to lateral load. The parameters obtained from the backbone curves are reported in Table 2. Results of the equivalent viscous damping υ eq , and the impairment of strength ΔF 1−3 are plotted in graphs which report in the horizontal axis the cycles and in the vertical axis the hysteretic parameters, see Figure 9 (a) and (b) which displays the results of SW and SW+PW configurations, respectively. Results of cyclic tests show that a maximum impairment of strength ΔF 1−3 about 33% was obtained in case of SW configuration, while a maximum impairment of strength ΔF 1−3 about 41% was obtained in case of SW+PW configuration. An average equivalent viscous damping of 5.60 and 8.26% was found for the SW and SW+PW configurations, respectively.

Fig. 7. Hysteresis loops and monotonic curves: (a) SW, (b) SW+PW configuration.

Fig. 8. a) Hysteresis loops and b) backbone curves obtained from cyclic tests.