1. PhD Student, Dept. of Constructions and Advanced Technologies, Univ. of Messina, Salita Sperone 31, 98166 Messina, Italy.
2. Associate Professor, Dept. of Mechanics and Materials, Univ. of Reggio Calabria, Via Graziella, Feo di Vito, Reggio Calabria, Italy (corresponding author).
3. Professor, Dept. of Structural Analysis and Design, Univ. of Napoli Federico II, P.le V. Tecchio 80, 80125 Napoli, Italy.
4. Professor, Dept. of Constructions and Advanced Technologies, Univ. of Messina, Salita Sperone 31, 98166 Messina, Italy.