Fuzzy modal finite element analysis of structures with imprecise material properties

This paper extends the fuzzy set theory to-a dynamic finite element analysi s of engineering systems which have uncertainties in material properties. A general algorithm which resolves the uncertain eigenvalue problem by using a reanalysis approach is considered. This algorithm is applied to the stud y of the modal behaviour of structures presenting uncertain material proper ties. Some indexes which determine the more sensitive eigenvalue to several uncertainty sources are also put forward. Finally, a plate structure as nu merical path-rest is analysed. The results of such a calculation determine the sensitivity of the modal behaviour to multiple simultaneous material pa rameters. (C) 1999 Academic Press.