TY JOUR TI ENERGY BEGINNING IN THE THEORY OF STRUCTURE SYNTHESIS KW rod system KW structural synthesis KW variational principles KW minimum of material volume JO Bulletin of Belgorod State Technological University named after. V. G. Shukhov AU Yuriev, A.G. AU Panchenko, L.A. PY 2023 IS 8 PB Belgorod State Technological University named after V.G. Shukhov