摘要
当模糊变量的隶属函数为正态型时,可以将模糊随机可靠性及可靠性灵敏度转化为随机可靠性及可靠性灵敏度,并利用复合函数求导法则求解模糊随机失效概率对正态型隶属函数分布参数的灵敏度。对于对称抛物型隶属函数,文中提出了"改进最大最小"法和"改进等面积"法两种近似等价正态化方法,从而将模糊随机可靠性问题转换为随机可靠性问题,并利用线抽样方法分析之。算例结果表明,由于"改进最大最小"法所得的等价正态型隶属函数能在函数图形尾部更好地近似对称抛物型隶属函数,因而"改进最大最小"法更适用于模糊变量的隶属函数为对称抛物型分布时模糊随机可靠性及可靠性灵敏度的近似计算。
In the case of the fuzzy variables possess Gaussian membership functions, the fuzzy random failure probability and reliability sensitivity can be transformed into the random ones. After that the chain rule was employed to obtain the sensitivity of the fuzzy random failure probability with respect to the distribution parameters of Gaussian membership function. For the symmetric parabolic membership function, the improved max-min method and the improved equivalent-area method were presented to transform the symmetric parabolic membership function to Gaussian one equivalently. The fuzzy random reliability problem can be transformed into the random one, which can be analyzed by the line sampling method. Since the symmetric parabolic membership function can be well approximated by equivalent Gaussian one based on the improved max-min method at the tail of the membership function graph, which is illustrated by the examples. Hence the improved max-rain method is more suitable for the estimation of the fuzzy random failure probability and reliability sensitivity, where the fuzzy variables possess the symmetric parabolic membership functions.
出处
《力学季刊》
CSCD
北大核心
2010年第1期83-91,共9页
Chinese Quarterly of Mechanics
基金
国家自然科学基金(NSFC50875213)
航空基础基金(2007ZA53012)
民口863计划(2007AA04Z401)
关键词
模糊随机失效概率
模糊随机可靠性灵敏度
对称抛物型隶属函数
改进最大最小法
改进等面积法
fuzzy random failure probability
fuzzy random reliability sensitivity
symmetric parabolic membership function
improved max-min method
improved equivalent-area method