Long-term reliability of structural systems

This paper develops the use of limit-state based reliability analysis techniques for long-term durability evaluation of structural systems. Failure modes related to strength deterioration, fatigue, corrosion, creep and wear are considered. Time-dependent reliability analysis is implemented for both component-level and system-level assessment. Combinations of analytical and sampling-based methods are pursued. For system-level assessment, an adaptive importance sampling technique is developed, and implemented in combination with commercial finite element analysis. In addition to computational reliability predictions, the updating of reliability estimates using non-destructive inspection data and Bayesian analysis is investigated. The proposed methodology is demonstrated with numerical examples related to aging civil structures and aircraft structures.