1. Postdoctoral Fellow, Dept. of Civil and Environmental Engineering, Univ. of Michigan, Ann Arbor, MI 48109-2125.
2. Professor, Dept. of Civil and Environmental Engineering, Univ. of Michigan, Ann Arbor, MI 48109-2125 (corresponding author).
3. Leader, Supervisory Research Structural Engineer, Structures Group of the Materials and Construction Research Division (MCRD) of the Engineering Laboratory (EL), National Institute of Standards and Technology, Gaithersburg, MD 20899-8611.