直升机动部件系统模态分析方法研究

Research on dynamic characteristic analysis of the Helicopter Dynamic Component System

直升机各级减速器及传动系统将发动机动力涡轮输出的功率传递给旋翼和尾桨。直升机上这些主要的动部件组成的系统称为直升机动部件系统。文章将直升机动部件系统划分为两个子系统:旋翼系统及动力/传动/尾桨系统。采用Hamilton原理推导桨叶在中等变形下的运动方程。经过多片桨叶组集,建立旋翼系统的动力学模型。简化动力/传动/尾桨系统力学模型,将传动轴处理为不具有转动惯量的弹性杆,动力涡轮、齿轮等处理为只具有转动惯量的刚性盘从而建立其动力学模型。在桨毂扭振自由度上将两个子系统进行耦合,建立直升机动部件系统动力学模型。在此基础上,以山猫直升机为例,分析直升机动部件系统耦合前后的模态变化。

The helicopter’s gearboxes and transmission system transmit the power output from the power turbine of the engine to the rotor and tail rotor.The system consisting of these main dynamic components of the helicopter is called the Helicopter Dynamic Component System(HDCS).HDCS is divided into two subsystems,rotor system and engine/drive/tail rotor system in this paper.The motion equation of blade under moderate deformation is derived by Hamilton principle.The dynamic model of rotor system is established through multi blade assembly.The mechanical model of the engine/drive/tail rotor system is simplified,the drive shaft is treated as an elastic rod with no moment of inertia,and the power turbine and gear are treated as rigid discs with only rotating inertia to establish its dynamic model.The rotor system and engine/drive/tail rotor system is assembled at the hub elastic torsion freedom.On this basis,taking the lynx helicopter as an example,the modal changes before and after coupling are analyzed.