1. Assistant Professor, Dept. of Structural Engineering, Faculty of Engineering, Univ. of Naples “Federico II,” P.le Tecchio 80, 80125 Napoli, Italy. E-mail: gdellaco@unina.it
2. Research Fellow, Dept. of Structural Engineering, Faculty of Engineering, Univ. of Naples “Federico II,” P.le Tecchio 80, 80125 Napoli, Italy. E-mail: lfiorino@unina.it
3. Full Professor, Dept. of Structural Engineering, Faculty of Engineering, Univ. of Naples “Federico II,” P.le Tecchio 80, 80125 Napoli, Italy. E-mail: fmm@unina.it