航空学报 > 2020, Vol. 41 Issue (9): 123761-123761   doi: 10.7527/S1000-6893.2020.23761

全模颤振双索悬挂系统刚体模态频率研究

吴太欢, 林麒, 何升杰, 柳汀, 高忠信, 王晓光   

  1. 厦门大学 航空航天学院, 厦门 361102
  • 收稿日期:2019-12-24 修回日期:2020-01-12 出版日期:2020-09-15 发布日期:2020-09-29
  • 通讯作者: 林麒 E-mail:qilin@xmu.edu.cn
  • 基金资助:
    国家自然科学基金(11472234,11702232);中央高校基本科研业务费专项资金(20720180071)

Rigid body modal frequencies of two cables suspension system for full-model flutter

WU Taihuan, LIN Qi, HE Shengjie, LIU Ting, GAO Zhongxin, WANG Xiaoguang   

  1. School of Aerospace Engineering, Xiamen University, Xiamen 361102, China
  • Received:2019-12-24 Revised:2020-01-12 Online:2020-09-15 Published:2020-09-29
  • Supported by:
    National Natural Science Foundation of China (11472234, 11702232); Special Funds for Basic Scientific Research Operating Expenses of Central Universities(20720180071)

摘要: 研究绳系结构和绳索预紧力对全模颤振双索悬挂系统刚体模态频率的影响。首先,基于绳索并联机构理论,对双索悬挂系统进行静力学建模,引入加权矩阵,推导了双索悬挂系统静刚度模型;其次,建立双索悬挂系统无阻尼振荡方程,分析双索悬挂系统刚体模态频率变化规律;进而,搭建了双索悬挂系统地面样机,开展系统模态频率测试试验,研究系统刚体模态频率的影响因素及其变化规律;最后,参考试验结果修正所建数学模型。结果表明,随着绳索预紧力的增加,系统刚体模态频率呈上升趋势,但各阶刚体模态的固有频率上升速率不同,平动模态的固有频率受绳索预紧力影响比转动模态小得多;在转动模态方面,滚转模态的固有频率最大且上升快;在平动模态方面,升沉模态的固有频率大于横侧滑模态的固有频率;双索经过的机身前后滑轮与飞机模型质心之间的相对位置变化会不同程度地影响支撑系统俯仰模态、偏航模态的固有频率,但几乎不影响其滚转模态的固有频率。研究发现,通过控制悬挂绳索预紧力的大小,合理设计机身上的滑轮安装位置,能够有效降低双索悬挂系统刚体模态频率。研究结果对于优化设计全模颤振双索悬挂系统具有指导意义。

关键词: 全模颤振, 风洞试验, 支撑系统, 双索悬挂, 固有频率

Abstract: In this paper, the influencing factors of the rigid body modal frequencies of two cables suspension systems for full-model flutter tests are studied. First, based on the rope parallel mechanism theory, the static model of the two cables suspension system is built. The static stiffness model of the system is then derived by introducing the weighting matrix. Second, the undamped oscillation equation of the two cables suspension system is established to analyze the changing laws of the modal frequencies of the system rigid body. Furthermore, a ground prototype of the system is established for the system modal frequency tests to study the influencing factors of the rigid body modal frequencies of the system and their changing rules. Finally, the above mathematical model is modified with reference to the experimental results. The results show that with the increase of the rope pretension force, the rigid body modal frequency of the system shows an upward trend, while the natural frequency at each order of the rigid body mode rises at different rates, with that of the translational mode being much less affected by the rope pretension force than that of the rotating mode, and that of the rolling mode being the largest and rising fast. In the translational mode, the natural frequency of the heave mode is larger than that of the lateral mode The positional relationship between the pulley and the mass center of the aircraft model affects the rate at which the natural frequencies of the support system pitch mode and yaw mode increase with the rope pretension force, though with different degrees of influence, while having almost no effect on the natural frequency of the rolling mode. The study has found that by controlling the pretension force of the suspension ropes and properly designing the installation positions of the pulleys on the fuselage, the rigid body modal frequencies of the two cables suspension system can be effectively reduced. Therefore, the results are instructive for the optimal design of the two cables suspension system.

Key words: full model flutter, wind tunnel tests, suspension systems, two cables suspension, natural frequencies

中图分类号: