1. Former Ph.D. Candidate, Dept. of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.
2. Senior Lecturer, Dept. of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K. (corresponding author).
3. Professor of Computational Structural Mechanics, Dept. of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.
4. Postdoctoral Research Assistant, Dept. of Engineering and Architecture, Univ. of Trieste, 34127 Trieste, Italy.
5. Associate Professor, Dept. of Engineering and Architecture, Univ. of Trieste, 34127 Trieste, Italy.
6. Professor of Structural Engineering, Dept. of Engineering and Architecture, Univ. of Trieste, 34127 Trieste, Italy.