Author(s):
1. Srđan Bošnjak, Univeristy of Belgrade, Faculty of Mechanical Engineering, Serbia
2. Zoran Petković, Univeristy of Belgrade, Faculty of Mechanical Engineering, Serbia
3. Miodrag Arsić, Belgrade, Institute for Material Testing, Serbia
4. Nebojša Gnjatović, Univeristy of Belgrade, Faculty of Mechanical Engineering, Serbia
5. Ivan Milenović, Univeristy of Belgrade, Faculty of Mechanical Engineering, Serbia