含间隙全动舵面的非线性颤振模式及被动抑制方法  

Nonlinear flutter modes and flutter suppression of an all-movable fin with freeplay

作　　者：白刘月 吴志刚[1] 杨超[1] BAI Liuyue;WU Zhigang;YANG Chao(School of Aeronautic Science and Engineering,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学航空科学与工程学院,北京100191

出　　处：《北京航空航天大学学报》2023年第9期2361-2373,共13页Journal of Beijing University of Aeronautics and Astronautics

摘　　要：间隙非线性环节广泛存在于飞行器的结构当中,由其引发的极限环振荡(LCO)往往造成结构的疲劳破坏,但目前关于全动舵面非线性颤振机理和被动抑制方法的研究相对较少。针对典型含扭转间隙小展弦比全动舵面开展分析,提出了2种典型的非线性颤振模式,并探索相应的非线性颤振被动抑制方法。基于描述函数法和活塞理论建立舵面的动力学模型,考虑到间隙非线性环节导致刚度降低的效果,计算对比了2种不同扭转刚度下全动舵面的非线性颤振特性,进而提出了2种不同的非线性颤振模式,其中,模式Ⅱ不存在稳定的极限环振荡过程,可以有效抑制低于线性颤振边界的极限环振荡问题;研究了舵面根部弯曲扭转刚度和质量特性对非线性颤振模式和极限环初始动压的影响,提出相应的非线性颤振被动抑制策略。针对所提算例,数值计算结果表明:通过调整舵面根部弯曲扭转刚度或质量特性可以提高极限环初始动压,甚至改变非线性颤振模式,从而达到非线性颤振抑制的目的。Freeplay nonlinearity widely exists in the structure of aircraft,which can bring limit cycle oscillations(LCO),leading to the fatigue failure of the structure.There is relatively little research on the mechanism and passive suppression of the nonlinear flutter for all-movable fins.Therefore,this paper proposes two different nonlinear flutter modes and provides passive suppression methods.The dynamic model is developed using the describing function method and piston theory.Considering that the torsional stiffness is reduced due to the existence of the freeplay,nonlinear flutter characteristics under different torsional stiffnesses are compared and two different nonlinear flutter modes are defined,in which modeⅡdoesn’t contain stable LCO,effectively suppressing the LCO below the linear flutter boundary.Then the influence of bending and torsional stiffnesses and mass moments of inertia on nonlinear flutter modes and the dynamic pressure of LCO appearance is studied,and some nonlinear flutter passive suppression methods are proposed.The findings indicate that reasonable adjustment of the bending and torsional stiffnesses or mass moments of inertia can raise the dynamic pressure of LCO appearance and even change the nonlinear flutter mode,so as to suppress the nonlinear flutter.

关 键 词：间隙非线性 非线性颤振 全动舵面 极限环振荡 颤振抑制 

分 类 号：V215.3[航空宇航科学与技术—航空宇航推进理论与工程]