TIME-DEPENDENT RELIABILITY OF STRUCTURAL SYSTEMS SUBJECT TO DETERIORATION

A probabilistic procedure for the analysis of the current and future r eliability of existing structural components and systems is developed: they are assumed subject to deterioration over time, due to the effec ts of ageing and of accidental events, such as thermal shocks or earth quakes. In particular, the following aspects are dealt with: the ident ification of probabilistic models for forecasting structural deteriora tion by ageing as a function of the initial and operating conditions a nd of the presence and nature of aggressive agents; the formulation of a probabilistic method for the assessment of the reliability of struc tural components subject to deterioration, that can be updated should maintenance or repair operations be carried out. The adopted approach involves the solution of a stochastic differential equation, which pro vides the time evolution of the reliability of a deteriorating structu ral component. Once the reliability of each structural element is; def ined, it is possible to evaluate the decreasing reliability of the str uctural system composed by these elements as a whole, taking into acco unt its operating and behavioral logic. (C) 1998 Elsevier Science Ltd. All rights reserved.