NONLINEAR WEIGHTED RESPONSE SURFACE IN THE SCATTERED FAILURE SUBREGION FOR FUZZY RELIABILITY ANALYSIS AND ITS APPLICATION

A novel method is proposed to analyze the fuzzy failure probability,usually referred as general failure probability. In the proposed method,the integral region of the fuzzy failure probability is scattered as finite subregions,where the membership of the performance function to the fuzzy failure regions are approximated as constants. Then the fuzzy failure probability is transformed into the random failure probabilities in the failure subregions,and the nonlinear weighted response surface method is proposed to calculate these random failure probabilities. The fuzzy failure probability analysis of the low cycle fatigue life of a turbine disk applied by cyclic loads is illustrated the proposed method. The results of the illustration show that the proposed method is efficient with an acceptable precision and applicable to the engineering problems.