1. Embraer - F20/1 2 Andar - SAR Av Brigadeiro Faria Lima, 2170 12227-901, Sa˜o Jose´ dos Campos, Sa˜o Paulo - Brasil
2. Department of Mechanical Engineering, Clemson University, 218 Fluor Daniel Building, Box 340921, Clemson, SC 29634-0921
3. Center for Intelligent Material Systems and Structures, Mail Code 0261, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061