ABSTRACT
This paper presents this decoupled approach in detail and demonstrates its applicability to complex bridge structural systems that are subjected to the risk of cascading failures induced by fatigue. Using a recursive formulation for describing limit-states of local fatigue cracking, the system failure event was described as a disjoint cut-set event (Lee & Song 2010). For example, the system failure event caused by the failure sequence {1→2→ … →i} for a given outcome X = x is described by
( )
(
⎡ ⎣ ⎢⎢
⎤ ⎦
⎡ ⎣
⎤ ⎦ ⎥⎥∀ ≠ ∀ ≠∩ ∩
( )1 ⎥⎥ ⎢⎢ ∩
)
(
T
T
⎡ ⎣ ⎢⎢
⎤ ⎦ ⎥⎥
+
∩ ∩ T T + .., ( ) )insT<
(1)
Many structural systems are subjected to the risk of cascading system-level failures initiated by local failures. For efficient reliability analysis of such complex system problems, many research efforts have been made to identify critical failure sequences with significant likelihoods by an eventtree search coupled with system reliability analyses; however, this approach is time-consuming or intractable due to repeated calculations of the probabilities of innumerable failure modes, which often necessitates using heuristic assumptions or simplifications.
