D.O. Bukleshev, Candidate, bukleshev_dima@mail.ru FSBEI HE «Samara State Technical University», Samara, Russia
It is established that the operation of pipelines on technical state requires the transition from periodic monitoring to continuous one without technological process shutdown. Changes of stressed-deformed state of the pipeline under the influence of operational and natural-climatic factors have significant effect on the strength of the structure. In addition, due to corrosion and mechanical loads, the centers of pipes corrosion cracking are emerging. The origin of corrosion cracks and their development occur very quickly and avalanche-like, and the nature and speed of propagation are hardly predictable.
Dependence of the tensile strength of weld-affected zones of the pipelines in a stressed-deformed state on the degree of corrosion damage is considered in the article. With the help of ANSYS software package, corrosion damage of the weld-affected zone was modelled and its maximum level was determined for safe operation of the pipeline using criterion of stress-deformed state and the tensile strength of pipe steel. Precise value of stress intensity at the top of corrosion crack was determined for pipe steel using the finite element method and computer simulation.
In the course of the conducted analysis the need and possibility of improving safety of pipeline transport were confirmed by studying the regularities of changes in the physical and mechanical properties of the base metal and welded pipe joints during operation. This will allow to more precisely determine the resource of structures in order to reduce the probability of accident and improve industrial safety of the main pipelines operation.
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