1. Ph.D. Student, Metal Structures Laboratory, School of Civil Engineering, National Technical Univ. of Athens, 9 Iroon Politechneiou str., GR-15780 Athens, Greece (corresponding author).
2. Associate Professor, Metal Structures Laboratory, School of Civil Engineering, National Technical Univ. of Athens, 9 Iroon Politechneiou str., GR-15780, Athens, Greece.