摘要
文中用三角级数法对不同谱宽系数的应力响应功率谱进行时域模拟,采用雨流循环计数方法获得应力幅值概率分布,比较了四种应力幅值概率密度函数模型对不同谱宽系数的应力循环雨流幅值分布描述的准确程度,并指定了各种应力幅值概率模型的适用范围。数值模拟结果表明:谱宽系数ε<0.3的窄带随机过程应力幅值服从Rayleigh分布;谱宽系数ε>0.5的宽带随机过程Dirlik概率模型比较准确的描述了应力幅值的概率分布;谱宽系数在0.3到0.5之间,给出的四种概率模型均不能较好的描述其应力幅值分布。
Four models of stress amplitude probability density function which were used to predict the random vibration fatigue life have been researched in this paper. First different stress power spectral of the coefficient of spectral width range from about 0.2 to 0.9 has been simulated in time domain by Trigonometry Series Method, and the corresponding stress amplitude distribution was acquired according Rainflow Method. Then the precision of the four models was discussed by comparing with the Rainflow stress amplitude distribution. The simulating results show that： the Rayleigh modal can be used to describe the stress amplitude distribution for narrow band process which the coefficient of spectral width is about smaller than 0.3, and dirlik model for wide band process which the coefficient is about higher than 0.5. But the four models can＇t describe the stress amplitude distribution exactly when range from about 0. 3 and 0. 5.
出处
《机械设计与研究》
CSCD
北大核心
2011年第6期16-20,共5页
Machine Design And Research
关键词
随机振动
疲劳寿命
谱宽系数
应力幅值分布:概率密度函数
random vibration
fatigue life
coefficient of spectral width
stress amplitude distribution probability density function
