Comparison of possibilistic reliability and stochastic reliability methods for uncertain structures

Traditional stochastic reliability method has been widely accepted and used in the analysis and design of the structures. A comparing possibilistic reliability method with the traditional stochastic reliability method is proposed. Firstly, we compared the two reliability methods in the modeling of uncertainties, model construction, and formulations for computation, etc. Then, we compared the structural optimization based on the reliability through a practical example. Some beneficial conclusions were obtained. Some results show that, if there is sufficient information to build an accurate model of uncertainties, the results of possibilistic reliability based on the optimization may will be consistent with the stochastic reliability method. Whereas, when little information is available to build an accurate stochastic model, the stochastic reliability calculation may lead to the large errors, but the possibilistic reliability procedure may offer safer results. It is demonstrated further that the possibilistic reliability method for the structures is reasonable, effective and useful.