PSI - Issue 17

Pedro Nunes et al. / Procedia Structural Integrity 17 (2019) 624–631 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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3.2. Relative displacements In Fig. 11, t he results regarding Δ u,max are presented. Like the other parameters studied, Δ u,max varied with T 1 /T 2 and seismic record used and tended to increase with the increase of AF. The peak RD obtained for AF = 1.0 is 76% and was obtained with the Isothermal model for T 1 /T 2 = 0.6. For AF = 2.0 and 3.0, peak RD of 72% and 70% were obtained, both when the Exp_LA3 model was used. With the Exp_T model, peak RD of 62% and 40% were obtained for AF = 2.0 and 3.0. These four values were obtained for T 1 /T 2 = 0.7. In global terms, values of RD less than or equal to 10% were obtained in 46% of the analyses, independently of the model used. These results indicate that Δ u,max is more sensitive to the characteristics of the SMA models than all other parameters focused. As can be seen in Fig. 12 (a) and (b), there is no correlation between the obtained RD and the values of u of frames 1 and 2. The maximum RD of 76% was obtained for T 1 /T 2 = 0.6 when both frames exhibited values of u close to 1. For all T 1 /T 2 , RD greater than 50% were obtained, what confirms that T 1 /T 2 may affect Δ u,max . The values of RD obtained tended to decrease with the increase of u , result also observed for the other parameters focused.

Fig. 11 – Influence of different SMA models on the values of Δ u,max

Fig. 12 – Sensitivity of the values of RD concerning Δ u,max to the ductility ratio of: (a) frame 1; (b) frame 2