薄壁圆管空间结构的热疲劳可靠性分析  

THERMAL FATIGUE RELIABILITY ANALYSIS FOR SPACE STRUCTURES COMPOSED OF THIN-WALLED TUBE

作　　者：阎彬[1] 陈建军[1] 方永锋[1] 曹鸿钧[1] 

机构地区：[1]西安电子科技大学电子装备结构设计教育部重点实验室,西安710071

出　　处：《固体力学学报》2013年第4期388-395,共8页Chinese Journal of Solid Mechanics

基　　金：国家自然科学基金项目(51175398)资助

摘　　要：针对薄壁圆管的空间结构,分析其在交变热载荷下的疲劳可靠性问题.为同时考虑由截面平均温度和截面温差造成的疲劳损伤,提出了综合利用剩余强度和疲劳累积损伤模型的分析方法.首先根据疲劳累积损伤相等原理,将截面温差造成的多级扰动应力载荷作用频次等效为平均温度下的常幅应力载荷作用次数,从而将两者产生的热应力载荷统一为一常幅载荷,再利用剩余强度模型基于动态应力-强度干涉理论对疲劳可靠度进行分析,得到了结构在综合考虑两种热疲劳状态下的动态可靠度.该方法可避免直接利用疲劳累积损伤理论临界损伤值难以确定的问题,且能体现金属疲劳损伤的真实情况.最后以哈勃望远镜为例,分析了其主梁随疲劳热载荷循环作用下的动态可靠度,得出了一些有意义的结论.The fatigue reliability of space structures composed of thin-walled tube element has been analyzed under alternating thermal load. To consider the fatigue damage due to both average temperature and temperature difference in cross section, an analytical method which uses the models of residual strength and fatigue cumulative damage is proposed. Firstly, according to the principle of fatigue cumulative damage equal, the frequency of multi-level disturbance stress load caused by temperature difference in cross section is equivalent to the times of constant amplitude stress load action under average temperature, thus all ther- mal stress loads will be unified for a constant amplitude load,then the fatigue reliability can be analyzed by using the residual strength model. Finally, the dynamic reliability of structures in the comprehensive con- sideration of two kinds of thermal fatigue state is obtained. This method avoids the problem that critical damage value is difficult to determine when directly using the theory of cumulated fatigue damage; even it can reflect the real situation for fatigue damage of metal. In the end,take Hubble Space Telescope as an ex- ample, the dynamic reliability of the main beam with the role of cycle fatigue thermal load is analyzed, some meaningful conclusions are drawn.

关 键 词：空间结构 疲劳可靠性 疲劳累积损伤 剩余强度 动态可靠度 

分 类 号：O346.2[理学—固体力学]