1. Senior Design Engineer and Drive System Analyst, Bell Helicopter, 600 East Hurst Blvd, Hurst, TX 76053.
2. Professor and Director, Center of Structural Engineering Research and Simulation Laboratory, The Univ. of Texas at Arlington, Arlington, TX 76019 (corresponding author).
3. Ph.D. Candidate, Center of Structural Engineering Research and Simulation Laboratory, The Univ. of Texas at Arlington, Arlington, TX 76019.