Cyclic loads affecting the durability of pipes for production wells gas

Abstract

The use of Chebyshev's polynomials of the first type to the strength of materials is based on probabilistic logic for the objective states of a metal. This is the case when "pure" science helps practical issues of objective reality. Due to this, it was noted that the metal undergoes a stable and unstable state during loading. The use of Chebyshev's polynomials of the first type has showed that the most stable state of the metal is shown by the Т9curve, at which the ratio б/б_т  = 0,5. This ratio is most favorable for pressure vessels, in contrast to the recommended American standard ASME, in which б/б_т  = 0,666 (this ratio reduces the reliability). Assessment of the state of the metal taking into account the frequency characteristics is more promising. This assessment confirms the frequency ratio б/б_т  ≈ 0,5 and allows taking into account inelastic phenomena in the metal, taking into account the loss coefficient, as well as to assess the possibility of resonance. The application of the control valve using the patent RU 2416751C1 allows achieving the optimal frequency of gas oscillations in the pipe and reducing the probability of resonance.