为进一步探究局部对旋式通风机叶轮结构的可能优化路径,以FBD No8.0/2×55 k W型对旋通风机为研究对象,通过三维建模和有限元分析方法,对该通风机叶轮进行力学分析与模态分析,根据分析结果确定叶轮结构需要改进的方向,而后采用NACA4...为进一步探究局部对旋式通风机叶轮结构的可能优化路径,以FBD No8.0/2×55 k W型对旋通风机为研究对象,通过三维建模和有限元分析方法,对该通风机叶轮进行力学分析与模态分析,根据分析结果确定叶轮结构需要改进的方向,而后采用NACA4415翼型叶片对叶轮结构进行优化,结果显示,优化后的叶轮叶片应力和应变显著降低,且发生共振的风险大大降低,表明本次分析与优化工作具有一定的现实意义。展开更多
Reticulated shell structures （RSSs） are characterized as cyclically periodic structures. Mistuning of RSSs will induce structural mode localization. Mode localization has the following two features： some modal vect...Reticulated shell structures （RSSs） are characterized as cyclically periodic structures. Mistuning of RSSs will induce structural mode localization. Mode localization has the following two features： some modal vectors of the structure change remarkably when the values of its physical parameters （mass or stiffness） have a slight change; and the vibration of some modes is mainly restricted in some local areas of the structure. In this paper, two quantitative assessment indexes are introduced that correspond to these two features. The first feature is studied through a numerical example of a RSS, and its induced causes are analyzed by using the perturbation theory. The analysis showed that internally, mode localization is closely related to structural frequencies and externally, slight changes of the physical parameters of the structure cause instability to the RSS. A scaled model experiment to examine mode localization was carried out on a Kiewit single-layer spherical RSS, and both features of mode localization are studied. Eight tests that measured the changes of the physical parameters were carried out in the experiment. Since many modes make their contribution in structural dynamic response, six strong vibration modes were tested at random in the experimental analysis. The change and localization of the six modes are analyzed for each test. The results show that slight changes to the physical parameters are likely to induce remarkable changes and localization of some modal vectors in the RSSs.展开更多
文摘为进一步探究局部对旋式通风机叶轮结构的可能优化路径,以FBD No8.0/2×55 k W型对旋通风机为研究对象,通过三维建模和有限元分析方法,对该通风机叶轮进行力学分析与模态分析,根据分析结果确定叶轮结构需要改进的方向,而后采用NACA4415翼型叶片对叶轮结构进行优化,结果显示,优化后的叶轮叶片应力和应变显著降低,且发生共振的风险大大降低,表明本次分析与优化工作具有一定的现实意义。
基金National Natural Science Foundation of China Under Grant No. 50878010
文摘Reticulated shell structures （RSSs） are characterized as cyclically periodic structures. Mistuning of RSSs will induce structural mode localization. Mode localization has the following two features： some modal vectors of the structure change remarkably when the values of its physical parameters （mass or stiffness） have a slight change; and the vibration of some modes is mainly restricted in some local areas of the structure. In this paper, two quantitative assessment indexes are introduced that correspond to these two features. The first feature is studied through a numerical example of a RSS, and its induced causes are analyzed by using the perturbation theory. The analysis showed that internally, mode localization is closely related to structural frequencies and externally, slight changes of the physical parameters of the structure cause instability to the RSS. A scaled model experiment to examine mode localization was carried out on a Kiewit single-layer spherical RSS, and both features of mode localization are studied. Eight tests that measured the changes of the physical parameters were carried out in the experiment. Since many modes make their contribution in structural dynamic response, six strong vibration modes were tested at random in the experimental analysis. The change and localization of the six modes are analyzed for each test. The results show that slight changes to the physical parameters are likely to induce remarkable changes and localization of some modal vectors in the RSSs.
