Оцінка залишкового ресурсу трубопроводів із зовнішнім корозійним дефектом при відмовах внаслідок втоми

Abstract

In this paper, the pipeline elbow with external corrosion defect with fixed dimensions has been considered. It is determined that plastic deformations may occur under the typical load in a structure with damage. The assessment of long-term strength was carried out on the basis of accumulation of low cycle fatigue. The kinetics of the accumulation of fatigue damage was determined within the framework of the concept of effective stresses of Rabotnov-Kachanov. Numerical estimation of the residual life-time of the elbow of the pipeline has been obtained, depending on the value of the pressure pulsation at nonstationary operating modes. Obtained values of the guaranteed life-time for the pipeline elbow with corrosion defects of various sizes.