Preliminary reliability analysis of a high-altitude airship’s envelope

To analyze the reliability of an airship’s envelope, the methodology of structural reliability analysis is adopted. The basic theory and the detailed steps of the algorithm of the first-order reliability method are discussed. For finding multiple design points, the method of adding bulge to the limit-state function is applied. With regard to the problem of envelope’s reliability, the safety criterion and limit state function of the airship’s envelope are analyzed. The mathematical model of the envelope’s maximum stress is also presented. The reliability simulation of a stratospheric airship’s envelope is taken as an example. Results of sensitivity analyses of the envelope are also obtained.