直升机动力学中参数振动问题的数值解法

NUMERICAL APPROACHES FOR SOLVING PARAMETRIC VIBRATION PROBLEMS IN HELICOPTER DYNAMICS

<正> 参数振动问题是直升机的基本动力学问题之一,旋翼桨叶的挥舞弯曲微分方程和摆振弯曲微分方程都是复杂的参数振动问题,在许多计论直升机旋翼动力学的论著中~[1-4],有的虽然推导了复尽杂的参数振动方程,却没有提到求解的方法,有的对此根本没有论及.本文旨在讨论参数问题的数值解法.

The parametric vibration problem is one of the fundamental problems in helicopter dynamics. The rotor blade flap bending differential equation and lag bending differential equation both are complex parametric vibration problems, especially the latter one. It is rather difficult to solve such a kind of blade motion equations. Two numerical approaches have been developed for solving the parametic equations. One is the periodic function method or harmonic method, and the other is the linear acceleration step-by-step integration procedure. The former has the advantage in saving CPU time and computer storge,but it can not be used to deal with the unsteady motion and investigate the infl'uence given by the initial condition. The linear acceleration step-by-step integration procedure can be used for steady or unsteady vibr at ion, bu t it takes more CPU time than the former. Two examples have been presented. They are solved by the periodic function method and linear accleration step-by-step integration procedure, respectively.