Papers by Keyword: Strength-Stress Interference Model

Abstract: According to the situation of randomness and fuzziness existing in the actual project, this paper proposed a reliability-credibility model based on fuzzy theory, possibility theory and credibility theory. At firstly, a reliability-possibility distribution curve was constructed by the traditional stress-strength interference model, then, a reliability distribution function was established based on this. This model built a bridge between credibility and reliability in handling randomness and fuzziness. The research results show that the model can hand the situation of random information and fuzzy information coexistence well, and the acceptable level of reliability and the most credible reliability value can be reflected directly in the reliability-credibility distribution curve. Compared with other methods, it obtains more reliability information, accords with the actual engineering situation and guides reliability engineering design much better.

Abstract: In this study, the reliability analysis of the low pressure steam turbine blade was performed using the Monte Carlo simulation considering variations of applied stress and strength. Applied stress under the service condition of steady state was obtained by finite element analysis. The fatigue strength under rotating bending load was evaluated by the staircase method. The most appropriate probabilistic distribution of the fatigue strength is 3-parameter Weibull distribution, which is determined by the comparative analysis. The failure probability under various loading conditions was derived from the strength-stress interference model.