1. Center for Mechanics of Solids, Structures, and Materials, Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, 210 E 24th Street, Austin, TX 78712
2. Center for Mechanics of Solids, Structures, and Materials, Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, 210 E 24th Street, Austin, TX 78712;
3. Department of Biomedical Engineering, The University of Texas at Austin, 107 W Dean Keeton St., Austin, TX 78712;
4. Texas Materials Institute, The University of Texas at Austin, 204 E. Dean Keeton St., Austin, TX 78712 e-mail: