TY JOUR TI STUDY OF THE FRICTION FACTOR OF POLYMER MATERIALS FOR 3D PRINTING OF ROLLING STOCK STRUCTURAL ELEMENTS KW technologies KW gearbox KW brakes KW rolling stock KW coefficient KW friction KW sealer KW sealing medium JO Transport engineering AU Osipov, D.V. AU Ivanov, P.Y. AU Dulskiy, E.Y. AU Pronin, K.E. PY 2023 IS 2023 PB Bryansk State Technical University