### 失调参数对T尾结构振动模态局部化的影响

1. 1.西北工业大学 航空学院 2.上海飞机设计研究所 强度室
• 收稿日期:2008-10-07 修回日期:2009-03-20 出版日期:2009-12-25 发布日期:2009-12-25
• 通讯作者: 杨智春

### Effect of Mistuned Parameters on Mode Localization of T-tail Structure

Yang Zhichun1, Yang Fei2

1. 1.School of Aeronautics, Northwestern Polytechnical University 2.Strength Department, Shanghai Aircraft Design and Research Institute
• Received:2008-10-07 Revised:2009-03-20 Online:2009-12-25 Published:2009-12-25
• Contact: Yang Zhichun

Abstract: Mode localization is often an unexpected dynamic phenomenon in weakly-coupled symmetric structures, and it arises from small imperfections (less than 5%) which perturb the symmetry of a structure. Such imperfections typically result from random manufacturing or assembly imprecision. Mode localization prediction is an important issue in T-tail structure design because drastic localized vibration phenomena may occur during the ground vibration test of a T-tail aircraft. Mode localization is dependent not only on parameter mistuning, but also on coupling degree. In this article the definition of mode localization is improved according to the peak amplitude ratio. The coupling degree is defined according to the effect of the stiffness of the horizontal stabilizer and fin on the modal frequencies of the T-tail structure. The mode localization and frequency loci veering phenomena for a T-tail structure is then studied and the effects of mistuned mass, mistuned stiffness and the location of mistuning on the mode localization of the horizontal stabilizer are investigated. Numerical simulation results for a T-tail structure model indicate that mode localization is most likely to occur in a T-tail structure consisting of weakly coupled substructures—a horizontal stabilizer and a fin. Moreover, when mode localization occurs, the first two bending vibration modes in the T-tail structure are prone to localization, and only one of the two modal frequencies is changed by parameter mistuning to induce frequency loci veering. The simulation also demonstrates that if mass or stiffness mistuning occurs to a horizontal stabilizer, the amplitude of the bigger mass side or smaller stiffness side is greater than that of the peer side. The study suggests that mode localization design is easy to achieve in T-tail structures by introducing mass mistuning on the tip of the horizontal stabilizer or stiffness mistuning on the root of the horizontal stabilizer.