飞机起落架滑行载荷识别

 在飞机滑行方向跑道路面不平度为平稳随机函数的假设下,采用滑行过程分段等速化、起落架动态特性分段线性化方法,把原非线性非平稳随机振动问题,简化为分段线性平稳随机振动问题。在频域中采用频响函数描述飞机动态特性,计及全机刚体平动和俯仰模态及结构前ｎ阶弹性模态,给出了从飞机重心处加速度观测值识别起落架接地点载荷自谱密度函数的方法。起落架当量线性参数采用迭代求解。算例表明,本方法和程序可行。

IDENTIFICATION OF AIRPLANE LANDING GEAR LOADS DURING TAXIING

On the assumption that the unevenness of runway profiles along the direction of taxi- ing is a stationary random function,techniques of piecewise constant-speed taxiing runs and piecewise linear representation of dynamic properties of airplane landing gears are adopted in this paper to approximately simplify the actual nonlinear and nonstationary random vibration prob-lems to the piecewise linear and stationary ones.By use of the frequency response functions to describe the dynamic characteristics of the airplane in the frequency domain,which include verti- cal translation and pitching modes of rigid body and the first n flexible modes of the airframe,a method of identifying the autospectral density functions of gear loads at the contact points with the runway from measured acceleration data at the centre of gravity of the airplane has been de- veloped in this work.The equivalent linear parameters of gear′s dynamic properties are obtained by iterative solution. Numerical results indicate that both the method and the program developed are feasible,which would be quite helpful to the design engineer particularly in evaluating fatigue damage of the structural system.