Moment Method Based Fuzzy Reliability Analysis for Wing of Unmanned Aircraft

Reliability analysis for wing of unmanned aircraft is a very important step in the process of unmanned aircraft design, but now most reliability analysis for wings are aimed at random reliability and ignored the fuzzy failure state. For fuzzy reliability analysis with fuzzy failure state and fuzzy safety state, moment method was proposed to calculate fuzzy reliability. In the integral operation of the fuzzy reliability, the integral. region was scattered according to the value of performance function. In the scattered integral region, the membership function value of the performance function to the fuzzy failure region keeps constant approximately, on which the calculation of the fuzzy reliability was transformed into that of the random reliability. After this transformation from the fuzzy reliability to the random reliability was completed, the moment method was employed to obtain he fuzzy reliability directly. The concept and the implementation of the proposed method are described in this paper, and the result of the wing of an unmanned aircraft shows that the proposed method possesses high precision and wide applicability in engineering.