【摘要】 提出广义失效概率估算的分段非线性加权响应面法。该方法首先将广义失效概率的积分区域划分为功能函数对模糊失效域隶属函数近似不变的积分微段,在积分微段中的广义失效概率可以转化为随机失效概率,进而采用非线性加权响应面法拟合积分微段边界,并求得相应边界的随机失效概率。针对0—起飞—0和0—最大连续—0循环载荷作用下的某型粉末冶金涡轮盘,采用文中所提方法对涡轮盘低周疲劳寿命进行模糊可靠性分析,分析结果表明,所提方法的效率、精度以及在工程上的实用价值。更多还原

【Abstract】 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.更多还原