摘要
针对工程中构件疲劳寿命估算存在的模糊现象,引入模糊理论中的隶属函数来描述疲劳极限附近的应力对构件造成损伤的模糊性,提出了应力模糊带的概念。并根据疲劳极限与应力模糊带边界的位置关系,将模糊带类型分为安全型、经济型和兼顾型。算例证明:将模糊理论应用于疲劳寿命分析中可以大大提高疲劳寿命预测的精度;选用安全型模糊带和升半正态分布隶属函数,且a=0.6σr,k=0.5时,与忽略模糊性的传统疲劳寿命预测方法相比误差可以减小38.7%。
For the fuzzy phenomenon during fatigue life estimation in engineering, membership function is used to denote the fuzziness of the fatigue damage by the stress nearby the fatigue limit. The concept of fuzzy zone of stress is put forward, and is classified as safety fuzzy zone, economy fuzzy zone and compatibility fuzzy zone by the rela- distribution in the calculation example with parameters a = 0. 6σ, and k = 0. 5, the error can be reduced by 38.7% compared with the traditional fatigue life estimation method of ignoring fuzziness.
出处
《机械科学与技术》
CSCD
北大核心
2008年第9期1139-1141,共3页
Mechanical Science and Technology for Aerospace Engineering
基金
国家自然科学基金项目(60472118)资助
关键词
疲劳寿命
隶属函数
应力模糊带
疲劳损伤
模糊理论
fatigue life
membership function
fuzzy zone of stress
fatigue damage
fuzzy theory
