STATISTICAL ESTIMATION OF RESIDUAL STRENGTH AND RELIABILITY OF CORRODED PIPELINE ELBOW PART BASED ON A DIRECT FE-SIMULATIONS

In this paper, the assessment of the effect of a corrosion defect, which is developing over time on the working capacity of the pipeline elbow, has been carried out. Corrosion damage models explicitly as volumetric defect on the out surface of the pipeline elbow. The zones on the damaged section of the pipeline on which the maximum stresses are localized has been defined using the finite element analysis. The estimation of the characteristics of the deformed state of a design with defect is analysed with the framework of computer simulations. On the basis of the obtained results, the probabilistic characteristics of the stresses and plastic strains have been approximated as a function of internal pressure and corrosion defect depth, such as mean value, coefficients of variation and asymmetry. Probability densities function of plasticity appearance have been found for different defect size in operation at typical loading levels.