NUMERICAL METHODOLOGY OF PREDICTION OF THE RELIABILITY AND RESIDUAL LIFE OF WELDED PIPELINE ELEMENTS WITH CORROSION-EROSION DEFECTS.

A set of procedures, mathematical models and tools for their finite-element realization were developed to solve typical practical tasks of expert analysis of the technological condition and residual safe operating life of welded elements of the main and technological pipelines with defects of corrosion-erosion metal loss detected during diagnostics. In order to lower the conservativeness of analysis, the interrelated processes of thermal deformation at assembly and repair welding, as well as initiation and propagation of subcritical damage of the defective structure material in the ductile mode in operation under complicated temperature-force conditions of external impact, were taken into account. Procedures of statistical analysis of fracture susceptibility of welded pipelines were developed on the base of Weibull and Monte-Carlo methods, and adequacy of the developed computational methods was confirmed. Peculiarities of the effect of welding on the reliability and serviceability of the main and technological pipelines with detected defects of corrosion-erosion metal loss were determined, in order to develop minimally conservative recommendations as to the possibility of safe operation of the pipelines. 18 Ref., 2 Tables, 12 Figures. [ABSTRACT FROM AUTHOR]