1. Research Fellow, Dept. of Mechanical & Structural Engineering, Univ. of Trento, Via Mesiano 77, 38050 Trento, Italy.
2. Associate Professor, Dept. of Structural Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
3. Professor, Dept. of Mechanical & Structural Engineering, Univ. of Trento, Via Mesiano 77, 38100 Trento, Italy.