摘要
前轮非线性摆振是由机轮的侧向振动与围绕支柱轴线的扭转振动相互耦合而形成的一种复杂的自激振动。当飞机滑跑速度超过某一临界速度时,前轮将会发生摆动并且一直发散到由支柱内的非线性项组合影响而形成的极限环上。本文利用描述函数法、多重尺度摄动法,研究了具有非线性阻尼M_(?)_1=C_1θ_1+C_(?)θ_1~2sgn(θ_1)的五自由度前轮非线性摆振系统,当超过飞机临界滑跑速度时极限环幅值的变化规律,并用数值分析方法予以验证。分析结果表明,采用较大的非线性阻尼可以抑制振幅过大的前轮摆振发生,而且上述三种方法得到的结果基本一致。
The nonlinear nose gear shimmy is complicated selfexcited vibration coupled with lateral oscillationand torsional oscillation around the center-line of strut.The nose wheel will oscillate and diverge to a limitcycle produced by the integrated influence of nonlinear terms in strut when the taxing speed of aircraft ex-ceeds a critical speed.This paper investigated the limit cycle amplitude of nonlinear shimmy system withthe nonlinear damping M_(0_1)=C_1θ_1+C_dθ_1~2sgn(θ_1)and with five degrees of freedom by describing functionmethod and by perturbation method when taxing speed exceeds a critical speed.The results from abovemethods were verified by numerical method.It is shown that the nose wheel shimmy with greater ampli-tude will be profected by greater nonlinear damping.The correlative analysis of above three methods wasgiven also.
出处
《振动工程学报》
EI
CSCD
1992年第4期384-390,共7页
Journal of Vibration Engineering
基金
国家教委博士基金资助课题
关键词
非线性振动
稳定性
起落架
摆振
nonlinear vibration
stability
landing gear
shimmy
