Review article

The influence of the ambient temperature on the dynamic characteristics of the above-ground main pipeline of large diameter is investigated. On the basis of the calculation scheme in the form of a thin-walled cylindrical shell and a geometrically nonlinear version of the semi-momentless theory of cylindrical shells, the frequencies of free vibrations are determined. The design scheme takes into account the joint influence of the internal working pressure, the parameter of the longitudinal compressive force, and the temperature. On the basis of the equation of motion in forces, taking into account the assumptions of the semi-momentum theory and external influences, the equation of motion in displacements is obtained. Boundary conditions are assumed to be hinged, pipes of medium length and long ones are considered in the range of length-to-radius ratio 8<L/R<15 from support to support. A study was made of the influence of temperature changes on the frequencies of free vibrations of above-ground gas pipelines for various values of the parameter of the longitudinal compressive force and geometric characteristics. The dependence of the change in the frequencies of free vibrations on the heating and cooling of the pipeline section is established, taking into account the combined effect of the internal working pressure and the parameter of the longitudinal compressive force.