A new possibilistic reliability index definition

In this work, a new and efficient definition for a reliability index is explored for real structural engineering problems. The main innovative aspect is that it is based on a possibilistic criteria instead of a probabilistic one. Its definition deals with engineering cases where uncertain parameters of basic structural reliability problems can be operatively treated as fuzzy variables. A fuzzy-based version of classic Cornell proposed reliability index is discussed. Consequently, differences and advantages with respect to other non-probabilistic reliability measures reported in literature are critically analyzed with reference to well-specified criterions. Finally, two numerical examples are illustrated. The first, in the framework of the materials strength problem, is a simple comparison between these fuzzy reliability indicators, and is developed to clarify the applicability of our proposal. Subsequently, another more realistic numerical example is proposed; it is developed to appreciate its effectiveness in reliability assessment of complex structural systems.