随机激励下高压管道的疲劳寿命分析

Estimation of fatigue life of pressure piping system under random excitations

应用功率谱密度 (PowerSpectralDensity)法对随机基础激励下高压管道进行疲劳寿命分析 .给出了在随机激励作用下结构的随机响应计算方法 ,由随机过程和Miner线性累积损伤理论 ,推导了功率谱密度法估算结构寿命的公式 .在此基础之上 ,以一飞机高压管道结构为例 ,编写程序求解出其疲劳寿命值 .算例表明 ,在某些结构的应力响应无法实测或难以实测到的情况下 ,采用功率谱密度法分析其疲劳寿命显得简洁有效 .

The fatigue life of pressure piping system under random base excitations was estimated by Power Spectral Density (P.S.D.) method. The computational method to achieve the random response was given for the structure under random excitations. The formula of estimating fatigue life by P.S.D. method was derived from the theory of random process and Miner linear damage rule. Based on this, the fatigue life of an aircraft pressure piping system was estimated as an example. The results showed that P.S.D. method was simple and effective to estimate the fatigue life of structures, especially for cases that the stress information of structures was difficult to gain or could not be obtained by actual measurements. The P.S.D. method was worth being popularized in the field of engineering.