A CALCULATION METHOD FOR ESTIMATING THE BEARING CAPACITY OF STRUCTURAL COMPONENTS OF GAS-MAIN PIPELINES

Abstract

Based on the main damaging factors, affecting the bearing capacity of the above-ground main gas pipelines, a new method of assessing the cyclic strength and durability of critical pipeline elements has been developed. Unlike the current method of point estimate only for strength, by the proposed new method, it is possible to perform calculations for strength and durability in the entire range of corrosion-fatigue cyclic stresses and durations. For this purpose, functional correlation of the coefficients of corrosion effect are obtained. A system of fatigue equations covering the entire range of corrosion fatigue (N=10¹...10⁸ cycles) is used and 2 calculation schemes are compiled: N1 – “air-corrosive medium”, N2 – “corrosive media 1 - corrosive media 2”, taking into account the influence of the corrosive environment and its option on the strength and durability. The intervals of cyclic overstresses and durations are identified to obtain a refined functional correlation of the characteristics of the bearing capacity of gas pipeline elements.