热声载荷下C/SiC层合薄板动态响应分析及寿命预测  

Dynamic response analysis and fatigue life prediction of C/SiC thin laminated plate under thermal-acoustic loadings

作　　者：白文君[1] 沙云东[1] 李华山[1] 唐晓宁[1] 

机构地区：[1]沈阳航空航天大学辽宁省航空推进系统先进测试技术重点实验室,沈阳110136

出　　处：《振动与冲击》2017年第10期76-83,共8页Journal of Vibration and Shock

基　　金：航空基础科学基金资助项目(02C54007)

摘　　要：鉴于处在热声载荷下的薄壁结构工作条件恶劣,极易发生屈曲和声疲劳从而影响构件的稳定性和使用寿命。以四边固支C/Si C复合材料层合板结构为研究对象,运用有限元方法计算结构在不同温度和声压级组合下的振动响应,分析屈曲前后响应特性并总结了典型的非线性振动响应特性;基于复合材料层合板高比强和特殊的结构疲劳损伤机理特点,运用改进的雨流法统计了层合板在超高温度强噪声工况下的应力响应,结合材料对称循环疲劳性能试验所得数据拟合地考虑平均应力影响的等效寿命公式和Palmgren-Miner线性累积损伤准则估算层合板的疲劳寿命。In view of the poor working environment of thin walled structures under thermal-acoustic loading conditions that are extremely easy to induce the buckling and acoustic fatigue and affect the stability and service life of components.A thin C/Si C composite laminated plate with four edges clamped was taken as an object examined.The finite element method was used to calculate the nonlinear random responses of the plate under various combinations of sound pressure levels and temperatures and typical thermal-acoustic motions were achieved.The response characteristics of the structure during buckling and post buckling were analysed and the typical nonlinear vibration response characteristics were summarized.In consideration of the high specific strength and special structural fatigue damage mechanism of composite laminated plates,the rain flow method was improved to count the stress responses of laminated plates under the condition of high temperature and loud noise.Making use of the performance data of material obtained in symmetrical cycle fatigue tests,the equivalent life formula for estimating the fatigue life of composite laminated plates was fitted,in which the mean stress effect was considered and the Palmgren-Miner linear cumulative damage criterion was adopted.

关 键 词：C/SiC层合板 热声载荷 应力动态响应 雨流法 疲劳寿命 

分 类 号：V214.8[航空宇航科学与技术—航空宇航推进理论与工程]