1. Senior Lecturer, School of Technology and Management, Polytechnic Institute of Leiria, Campus 2, Morro do Lena, Alto do Vieiro, Apartado, 4163-2411-901 Leiria, Portugal (corresponding author).
2. Researcher, Faculty of Engineering, Dept. of Civil Engineering, Structural Division, Univ. of Porto, R. Dr. Roberto Frias, 4200-465 Porto, Portugal.
3. Associated Professor, Faculty of Engineering, Dept. of Civil Engineering, Structural Division, Univ. of Porto, R. Dr. Roberto Frias, 4200-465 Porto, Portugal.