Abstract: A method using fuzzy optimization to identify the joint parameters of the mechanical structure is presented, which is based on the combination of the experimental test results of the whole structure system with the finite element models of the substructures. The theoretical formulas and numerical analysis are shown in this paper. In this method the influence come from different modals to the different joint parameters are taken into consideration via the weighted factors, at the same time the fuzzy equation is used in this method based on the consideration that there exist some uncertain errors both in the experimental values and finite element models. The numerical results demonstrate that the new method can overcome the disadvantages of the least squared method that uses the definite equation with the experimental values and finite element models and without weighted factors and can get accuracy results.

Key words: joint surface , parameters identification, fuzzy optimization