%0 Journal Article %T APPLICATION OF ISOGEOMETRIC APPROXIMATION BY CUBIC SPLINES IN THE CALCULATION OF THREE-DIMENSIONAL STRUCTURES BY THE VARIATIONAL METHOD %A Sahbiev, O.M. %A , .. %K APPROXIMATION, FUNCTION APPROXIMATION, CUBIC SPLINES, ISOGEOMETRIC APPROXIMATIONS, VARIATIONAL CALCULATION METHOD, THICK PIPE %J Herald of Technological University %D 2026 %N 29 %P 4 %I Kazan National Research Technological University