TY JOUR TI Computer simulation of hard-to-machine billet cutting using digital twins KW cutting KW hard-to-machine materials KW titanium alloys KW digital twin KW energy readings JO Science intensive technologies in mechanical engineering AU Kiselev, E.S. AU Ilyushkin, M.V. AU Savel'ev, K.S. PY 2021 IS 2021 PB Bryansk State Technical University