**Author details**

)

) provides the mini-

) provides the greatest torsional stiffness, but

Sergey Shevtsov<sup>1</sup> \*, Igor Zhilyaev1 , Natalia Snezhina<sup>2</sup> and WU Jiing-Kae3

\*Address all correspondence to: sergnshevtsov@gmail.com

1 South Center of Russian Academy, Rostov on Don, Russia

2 Don State Technical University, Rostov on Don, Russia

3 National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan R.O.C.
