1. Smart Structures Laboratory, Department of Aerospace Engineering, University of Maryland, College Park, MD 20742, USA
2. Department of Aerospace Engineering, Old Dominion University, Norfolk VA 23529, USA
3. Advanced Technology Division, Techno-Sciences, Inc., Beltsville, MD 20705, USA
4. Smart Structures Laboratory, Department of Aerospace Engineering, University of Maryland, College Park, MD 20742, USA,