Development of a Probabilistic Model for Mechanistic Evaluation of Reliability of Oil Pipelines Subject to Corrosion-Fatigue Cracking

摘要

A model structure for the corrosion-fatigue degradation phenomenon has been proposed for oil pipelines. At first, a well acknowledged model for corrosion-fatigue, such as Wei's "Super Position Model", was pursued as a reference. By reiterating the reference model using generic data from literature and applying Monte Carlo simulation, the simplest possible structure for the model was identified. The correlation of the proposed model with the environmental effects, such as loading stress and frequency, surrounding the pipelines were estimated. The sources of random variability emerging from many sources have been reasonably embodied into only two random variables. Yet again, the scarce of field and experimental data for this particular critical degradation phenomenon has compelled the research study to rely profoundly on generic data from open literature. Hence, the best distribution estimates for the two random variables were computed. Subsequent to number of iterations, the proposed model was modified to rather simpler form. All the proposed model forms have been cross checked against the original reference model which resulted in a satisfying agreement.