【作者】 胡宇；

【导师】 董石麟； 陈务军；

【作者基本信息】 上海交通大学 ， 土木工程， 2012， 硕士

【摘要】 空间薄膜具有轻质、抗振性好等优点,可用于研制深空探索太阳帆、薄膜天线等航天器。空间薄膜阵面刚度主要决定于边缘几何线型和预应力。预应力分析是薄膜结构分析基础,预应力导入效应及其影响分析是薄膜结构预应力研究重要内容。本文针对大型空间薄膜阵面研究对象,开展薄膜阵面预应力分析、刚度影响因素、振动模态试验、褶皱分析等研究。本文以39066mm? 9894mm空间薄膜阵面结构为数值分析对象,对该结构各部分及整体进行模态分析,研究阵面结构合理方案,研究空间薄膜阵面结构模态及结构特征分析。为了指导工程实践,研究了薄膜阵面结构刚度影响因素。分别考虑薄膜阵面面密度、预应力影响。在面密度分别为150 g/m2、200 g/m2、200 g/m2时,预应力分别为18 psi、25 psi、50 psi,其对应基频增大23.1%、22.2%、18.9%;在相同预应力而对应三种面密度,基频降低11.5%、9.1%、14.8%。可见预应力变化比面密度变化对基频有更大影响。在对该空间薄膜阵面刚度数值模拟之后,需要薄膜结构模态试验验证。采用25 ?m Mylar薄膜,设计制作了边缘为圆曲线、矢跨比为210,平面尺寸为325 ? 445mm的阵面模型,应用航天805所研制张力机构实现膜面张力加载,采用激光测振分析仪进行了模态试验辨识,并与数值模拟结果对比。试验结果表明,试验膜面振型与数值模拟结果基本吻合,但对应频率有较大差异。以空间薄膜阵面结构预应力膜面为对象,研究大型薄膜阵面褶皱行为特征,分析了阵面几何、预应力、初始缺陷、非均匀节点张力等对薄膜褶皱的影响。论文最后对本文的研究成果进行了总结,并指出了今后的研究方向。更多还原

【Abstract】 The space planar film reflect-array that can be used for space solar sail for exploration and radar antenna, is gaining more and more research attention for its remarkable characteristics as light in weight, well in vibration resistance.Space film reflect-array stiffness depends mainly on the shape of edge and value of pre-stress. Structural analysis of film is based on the analysis of pre-stress, the key area of analysis of film structural pre-stress is effect and influence factors of film structural with pre-stress imported. This paper, based on a specific film reflect-array structure as the object of investigation, analyzes several aspects including structural pre-stress of film reflect-array, the film reflect-array structural influence factors, film reflect-array wrinkling, numerical simulation and verification of film vibration test.Space film reflect-array, whose outline dimension is 39066mm? 9894mm,is used as the numerical object, whose structural characteristics and modals are analyzed by breaking up the film reflect-array structure. Moreover, the whole structural model is also analyzed, and the reasonable structural type of the film reflect-array is as well as considered.In order to guide practice of engineering,the effect factors of overall structural rigidity of the pre-stress of film reflect-array is considered. Structural modals of film reflect-array are calculated when the aerial density of film reflect-array is individually 150 g/m2,200g/m2,200 g/m2 and pre-stress of film reflect-array is 18psi,25psi,50psi,the frequencies of film reflect-array increase by 23.1%,22.2%,18.9%.When pre-stress of film reflect-array is the same ,the three aerial densities decrease by 11.5%,9.1%,14.8%.It can be seen that there are greater influences variation of pre-stress of film reflect-array than variation of the aerial density of film reflect-array. After the stiffness of the space film reflect-array be calculated, experimental verification of film structural modal is required. The circular curve film reflect-array, which is made from 25?m Mylar and whose outline dimension is 325?445mm, at edge rise-span ratio 210 is designed, and mechanism of tension which was developed by Shanghai Aerospace System Engineering Institute is used to load the film reflect-array, however, laser vibrometer is used to identify modals. Modals are compared to the results of numerical simulation. The result of test shows that the shapes between experimental modal and numerical simulation are consistent,but there are difference frequencies value among the corresponding modals. Space film reflect-array is used as the numerical object, and thebehavior characteristic of large film reflect-array is considered, and analyzes several effect factors on producing wrinkle including geometry of film reflect-array、pre-stress of film reflect-array、initial defect、the node of non-uniform tension.In the final part of this paper, the research is summarized, and the future developing direction is pointed out.更多还原