1. International Research Center on Mathematics and Mechanics of Complex Systems; Università dell'Aquila; Cisterna di Latina Italy
2. Department of Structural and Geotechnical Engineering; Università di Roma La Sapienza; 18 Via Eudossiana Rome Italy
3. Department of Mechanical and Aerospace Engineering; Università di Roma La Sapienza; 18 Via Eudossiana Rome Italy
4. Université de Lyon-INSA; 20 Av. Albert Einstein Villeurbanne cedex France