1. Postdoctoral Researcher, Dept. of Civil and Environmental Engineering, Northwestern Univ., Evanston, IL 60208; Postdoctoral Scholar, Dept. of Civil Engineering, İstanbul Teknik Üniversitesi, Istanbul 34469, Turkey.
2. Chair of Joint ACI/ASCE 446 Committee, Fracture Mechanics; Associate Professor, Dept. of Civil and Environmental Engineering, Case Western Reserve Univ., Cleveland, OH 44106.
3. Past Chair of Joint ACI/ASCE 446 Committee, Fracture Mechanics; Professor, Dept. of Civil and Environmental Engineering, Northwestern Univ., Evanston, IL 60208.
4. McCormick Institute Professor and W.P. Murphy Professor of Civil and Mechanical Engineering and Materials Science, Northwestern Univ., Evanston, IL 60208 (corresponding author).