Sergey L. Golofast
The paper presents the results of studies of the mechanical properties of the material of pipes made of 17G1S steel by various manufacturers of tubular products, and an assessment of the influence of these properties on the strength reliability of main pipelines. Results processing of studies for mechanical characteristics of pipe steels and the calculation of the probability of failure-free operation of main pipeline linear sections according to the strength criterion are based on the mathematical apparatus of non-parametric statistics, taking into account the actual distribution laws of the random variables under study.
Materials and methods
Processing of the results of experimental studies of the strength characteristics of pipe steels and the evaluation of the strength reliability of main pipelines linear sections was carried out on the basis of non-parametric statistics methods.
As a result of experimental studies of samples cut from pipes made of 17G1S steel by various manufacturers, it was found that the limits of dispersion and patterns of change in the pipes material strength characteristics have significant differences. Calculations performed on the basis of experimental data indicate that the random nature and individual laws and distributions of strength characteristics for each grade of pipe steels have a significant influence on the accuracy of estimating the strength reliability of main pipelines linear sections.
Assessment of strength reliability and risk of safe operation of trunk pipelines should be carried out individually for each linear section on the basis of an approach that takes into account actual patterns and limits of changes in the strength characteristics of pipe steels and external load parameters. To increase the reliability of the results of assessing the strength reliability of linear sections of trunk pipelines, it is necessary to create a database containing statistical information on the strength characteristics of the pipe material, taking into account such factors as the release date, manufacturer, specifications or standards for tubular products, duration and operating conditions.