Stochastic and nonlinear-based prognostic model

The prevention of failure and the evaluation of products state are the most important aims for industrialists since nonpredicted failure is very expensive in most cases. These can be done mainly by the evaluation of the “Remaining Useful Lifetime” (RUL) using the prognostic approaches that compensate the inconveniences of classical maintenance strategies. A proposed analytic prognostic methodology based on nonlinear damage laws is developed here to determine the RUL of the system. It permits to ensure a high availability and productivity with less cost for industrial systems. To make this approach more reliable, it is essential to introduce the stochastic description. In the case of the fatigue effect where the damage state is growing from macro-cracks to total failure, D(N) expresses an increasing scalar damage function in terms of loading cycles N. The RUL is estimated from a predefined threshold of damage DC. Pipelines tubes, subject to fatigue effects due to pressure–depression alternation, belong to vital mechanical systems in petrochemical industries that serve to transport natural gases or liquids. The prognostic evaluation of their states increases the tubes performance and the availability while minimizing their mission cost.