TY JOUR TI CALCULATION OF CENTRALLY COMPRESSED CONCRETE FILLED STEEL TUBULAR COLUMNS OF ANNULAR SECTION TAKING INTO ACCOUNT PHYSICAL NONLINEARITY KW pipe concrete KW annular section KW bearing capacity KW deformation theory of plasticity KW finite difference method KW physical nonlinearity JO Construction and Architecture AU Khashkhozhev, K.N. AU Avakov, A.A. PY 2021 IS 9 PB Publishing Center RIOR