随机声载荷作用下的复杂薄壁结构Von Mises应力概率分布研究  

Probability distribution of Von Mises stress for complex thin-walled structures undergoing random acoustic loadings

作　　者：沙云东[1] 郭小鹏[2] 廖连芳[2] 解丽娟[2] 

机构地区：[1]沈阳航空航天大学辽宁省数字化工艺仿真与试验技术重点实验室,沈阳110136 [2]沈阳发动机设计研究所,沈阳110015

出　　处：《振动与冲击》2011年第1期137-141,共5页Journal of Vibration and Shock

基　　金：航空基础科学基金资助基金项目(02C54007)

摘　　要：随机声载荷作用下的某些复杂薄壁结构的振动疲劳属于多轴疲劳,Von Mises应力准则是多轴疲劳损伤分析的一条有效途径。通过对有限带宽高斯白噪声载荷作用下结构Von Mises应力概率分布研究,分析提出Von Mises应力服从双参数Weibull分布或Lognormal分布,并且给出了估算这两种概率分布参数的方法,进而得到了Von Mises,应力峰值概率密度函数,从而为结构的疲劳损伤寿命估算提供依据。在工程应用中采用耦合的有限元和边界元方法计算了某型航空发动机燃烧室火焰筒薄壁结构在随机声载荷作用下的振动应力响应功率谱密度,着重分析了Von Mises应力响应的概率分布特征,并对分析结果采用Kolmogorov-Smirnov(K-S)检验进行了比较验证。The vibratory fatigue of some complex thin-walled structures undergoing random acoustic loadings is typically a multiaxial fatigue problem, and it is an effective approach to conduct a multiaxial fatigue damage analysis with Von Mises stress criterion. The probability distribution of Von Mises stress was investigated here for structures under band- limited Gaussian white noise loadings. The hypothesis was proposed that Von Mises stress obeys two-parameter Weibull distribution or Lognormal distribution, and the method for estimating the parameters of the two kinds of probability distribution was developed. As a result, the peak value probability density functions of Von Mises stress could be calculated, and these functions could be used as the basis for estimating the structural fatigue life. In engineering application, by using a FEM/BEM coupled method, the power spectral density （PSD） of the vibrational stress response of the thin-walled structure of an aeroengine combustor liner under random acoustic loadings was calculated, the probability distribution characteristics of Von Mises stress were analyzed emphatically, and the results were comparatively validated with Kolmogorov-Smirnov （K-S） test.

关 键 词：火焰筒 薄壁结构 声疲劳 Von Mises应力 概率密度 

分 类 号：V215.5[航空宇航科学与技术—航空宇航推进理论与工程] V232.6