TY JOUR TI THE INFLUENCE OF THE OUTER SHELL ON THE STRENGTH OF AN FDM ROD WITH A LOW FILLING PERCENTAGE KW additive technologies KW FDM printing KW sample KW tensile testing KW the outer shell JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Raspopina, V.B. AU Martynova, V.V. PY 2026 IS 11 PB Belgorod State Technological University named after V.G. Shukhov