Nonparametric reliability analysis for design of a mechanical system working on an inaccessible area

Abstract

Nonparametric (distribution-free) reliability analysis (RA) is suggested as an alternative for RA of a mechanicalsystem working on an inaccessible area, for instance, vehicle traveling on deep-seabed. Generally, it is not easy toestimate the appropriate statistical distribution function on the base of sample data, especially noise orenvironmental factors. Since the probability distributions of noise random variables are not often known and onlya few sample data is given for design of a mechanical system working on the inaccessible area, the usage ofnonparametric estimation is an emerging method to estimate the reliability of the system. Nonparametric RA isdefined as reliability estimation of performance function from nonparametrically estimated distribution of noiserandom variables. A mathematical example is illustrated to compare the characteristics of nonparametric RA withthose of parametric RA. Test statistic for estimated distribution of a noise random variable and reliability accuracyat a design point are used for evaluation of the performance and robustness of each RA. It is concluded that thenonparametric RA is more robust then the parametric RA for few sample data of stochastic variables.