System reliability assessment of ductile frame structures using methods of moment

Abstract

Reliability assessment of ductile frame structures in a systematic manner has remained a challenging issue because of the difficulties in searching for important failure modes and evaluating the system probability of failure stemmed from these important modes. In this paper, based on the Box-Cox transformation, a new failure mode independent performance function with the probability distribution of weak non-normality is proposed for the system reliability assessment of ductile frame structures. An efficient approach is then developed for estimating the failure probability of the proposed performance function, which includes two steps: first, the point-estimate method based on hybrid dimension-reduction integrated with structural limit analysis is developed to evaluate the first four central moments (i.e., mean, standard deviation, skewness, and kurtosis) of the proposed performance function; next, the system probability of failure corresponding to the proposed performance function is then estimated using the moment-based reliability method. Three numerical examples are presented to demonstrate the efficiency and accuracy of the proposed method, where the method of subset simulation is employed for comparison. It can be concluded that the developed methodology successfully overcomes the two difficulties including the identification of important failure modes and the evaluation of system probability of failure stemmed from these important modes in system reliability assessment of ductile frame structures.