[1] Univ Tras Os Montes & Alto Douro, Sch Sci & Technol, ECT UTAD, P-5000801 Vila Real, Portugal
[2] Univ Porto, Fac Engn, Mech Engn Dept, INEGI LAETA, P-4099002 Porto, Portugal
[3] Univ Penn, Sch Engn, MEAM Dept Mech Engn & Appl Mech, Philadelphia, PA 19104 USA