Reliability assessment of complex structural systems

A strategy for the reliability assessment of a complex structural system subject to deterioration is illustrated, where the term “complex” is related both to the lack of an analytical model of the structural response and to the computational burden that is needed to evaluate the effects of deterioration. The proposed procedure allows to take into account the uncertainties of the input parameters, as well as the model uncertainty; this aim is attained by implementing an advanced simulation technique, that consists in coupling Latin Hypercube Sampling and Simulated Annealing. As a case example, the reliability of the prestressed concrete containment vessel of a nuclear reactor, subject to a Loss of Coolant Accident, is assessed, in order to evaluate the effect of structural deterioration on the chance of prolonging the operational lifetime of the plant