COMPUTATION OF TIME-DEPENDENT STRUCTURAL SYSTEM RELIABILITY WITHOUT USING GLOBAL LIMIT STATE FUNCTIONS

For time-independent reliability problems where structural materials a re constant, the limit state functions generated by identifying failur e modes can be used throughout the entire computation procedure. Howev er, when structural materials (resistance) vary with time, as the case explored in structural deterioration problems, the limit state functi ons may change accordingly, since the failure sequence (modes) may cha nge. The intention of the present paper is to propose an alternative a pproach which computes the time-dependent structural system reliabilit y without the use of global limit state functions for the structural s ystem, In this approach, the reliability analysis of structural system s is based on the reliability of the structural components which const itute a failure sequence for the system, The main advantage of the pro posed approach is that it significantly simplifies the entire computat ion procedure, since the generation of limit state functions for struc tural systems has been, and still is a major issue in structural syste m reliability analysis, Examples are given to illustrate the approach.