Feasibility of FORM in finite element reliability analysis

The context for this paper is the growing need for reliability analysis in conjunction with advanced finite element models. This type of analysis is useful in many civil engineering applications to account for uncertainties by estimating the probability of response events, with all input parameters given as random variables. Compared with traditional structural reliability applications, such analyses carry unique opportunities and challenges. In this paper, emphasis is placed on the first-order reliability method due to its appealing tradeoff between accuracy and computational efficiency. The viability of this reliability method is studied in the context of both static and dynamic finite element problems. For static problems, a list of hypotheses is put forward to help the analyst identify potential pitfalls and remedies. Additional challenges appear in dynamic problems. In this paper, a novel limit-state formulation is considered in conjunction with dynamic loading and inelastic material models. The formulation is based on cumulative response measures, which arguably are the governing measures of structural performance in many applications. The new approach effectively addresses the time-variant structural reliability problem.