开孔氧化铝薄膜／铝合金基体热屈曲变形和应力分析  

Thermal Flection Distortion and Stress Analysis in Alumina Film/Al-alloy Substrate by Finite Element Method

作　　者：弓满锋[1,2] 乔生儒[3] 梅芳[2] 袁月清[2] 

机构地区：[1]西北工业大学超高温结构复合材料国家级重点实验室,西安710072 [2]湛江师范学院机电工程系,湛江524048 [3]1西北工业大学超高温结构复合材料国家级重点实验室,西安710072

出　　处：《材料导报》2009年第14期1-4,共4页Materials Reports

基　　金：国家自然科学基金资助项目(50772089);高等学校学科创新引智计划资助(B08040);湛江师范学院科研资助项目(L0807)

摘　　要：假设薄膜和基体界面处于理想结合状态,基于应变协调理论,采用有限元软件(ANSYS8.0)分析了不同膜基比(hc/hs)和开孔对氧化铝薄膜/铝合金基体系统热屈曲变形、热应力的影响。结果表明,当矩形薄板发生热屈曲时,曲率和热应力均随膜基比非线性变化。随着膜基比的增加,曲率不断减小,而薄膜和基体中的热应力表现出不同的变化趋势,基体中的热应力随膜基比的增加而增加,薄膜中的热应力随膜基比的增加而减小。当hc/hs<0.005时,曲率受膜基比的影响非常大且曲线较陡;当hc/hs>0.005时,曲率随膜基比的增加而缓慢减小。开孔能在一定程度上缓解系统的热屈曲变形,但是这种缓解程度相对较小。无孔时系统中的热残余应力在面内基本上都是均匀分布的,而开孔时系统中的热残余应力分布不再均匀,特别是在小孔附近产生了严重的应力集中现象,膜基比越小则应力集中现象越严重。The interfaces of Al2O3 film and Al-alloy substrate are supposed in a perfect status, which is based on the strain harmony theory. A finite element software （ANSYS 8. 0） has been used to analyze the thermal flexion distortion and thermal residual stress for the Al2O3 films/Al-alloy substrate system, which are affected by the hc/hs and small circle hole in the substrate. The results show that the curvature and the thermal residual stress nonlinearly change with the hc/hs value, when thermal flexion occurs on the rectangle thin plate. The curvature decreases with the hc/hs value increasing, but the thermal residual stress shows the different changed-trend. The stress in Al2O3 films decreased with the increase of hc/hs, the stress in substrate, however, increases with it. The curvature is greatly affected by the hc/hs and the change is very steep when hc/hs〈0. 005; the curvature is slowly decreased with the hc/hs value increasing and the change is also less when hc/hs〉0. 005. It can relax the thermal flexion distortion by opening a hole in substrate, but the affected extent is less. The thermal residual stress uniformly distributes in plane with no hole in substrate, but that does not uniformly distribute in plane with a hole in substrate. The serious stress concentration phenomenon takes place near the hole, the less hc/hs value is the more serious this phenomenon is.

关 键 词：氧化铝薄膜 铝合金 热屈曲 变形 应力 有限元 

分 类 号：TB125[理学—工程力学] TB332[理学—力学]