1. National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Mechanics, Zografou Campus, 5 Heroes of Polytechneion Avenue, 157 73, Attiki, Greece
2. National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Mechanics, Laboratory of Strength and Materials, Zografou Campus, 5 Heroes of Polytechneion Avenue, 157 73, Attiki, Greece