PSI - Issue 78

Marco Terrenzi et al. / Procedia Structural Integrity 78 (2026) 418–425

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Figure 3 shows the IF model’s results. The trend lines reveal negligible average di ff erences between k init and k comm , suggesting that the choice between these two sti ff ness formulations is less critical for the IF model compared to the BF model. Consistent with the BF case, employing k init resulted in smaller displacements.

3.2. NTHAs with Modal Damping

The second approach employed was Modal Damping. Similar to the Rayleigh damping analyses, simulations were performed with ξ n ranging from 1% to 5%, applied uniformly across the first 10 modes.Figures 4 and 5 illustrate the impact of modal damping on the BF and IF buildings, respectively. For the BF building (Figure 4), modal damping notably reduces the response more significantly in the X-direction (stronger) than in the Y-direction (weaker).

Fig. 4: NTHAs of the BF model with Modal damping: maximum RD in the X and Y directions with linear trend lines

Fig. 5: NTHAs of the IF model with Modal damping: maximum RD in the X and Y directions with linear trend lines