This study provides a novel method for reliability analysis of structural systems. Its
main feature is the decomposition of an original multiple limit states reliability
problem into the sum of a number of single limit state reliability problems. An exact
equation is derived for the evaluation of the probability of system failure
under three assumptions: the number of system failure modes is finite, the
structural system is subjected to mutually exclusive and collectively exhaustive
failure modes, and components connected in parallel have perfectly correlated
failures with causal relationship. The validity of the derivation is demonstrated
mathematically. The concept of global probability of system failure is introduced to
assess the reliability of structural systems subjected to multiple loading
conditions. Example applications are presented. The results show that the
proposed method is effective for a large variety of structural systems and can
be applied considering either all the failure modes or only the dominant
ones.
