1. Ph.D. Student in Civil Engineering, School of Engineering and Design, Brunel Univ., Uxbridge, Middlesex UB8 3PH, U.K.
2. Senior Lecturer in Civil Engineering Design, School of Engineering and Design, Brunel Univ., Uxbridge, Middlesex UB8 3PH, U.K. (corresponding author).
3. Senior Lecturer in Computational Mechanics, School of Engineering and Design, Brunel Univ., Uxbridge, Middlesex UB8 3PH, U.K.