无人直升机主桨毂中央件疲劳试验载荷调试技术

Loading Adjustment Technology about Main Rotor Hub of Unmanned Helicopter in Fatigue Test

针对某新型无人直升机主桨毂中央件的桨毂构型和承载特点,探究和分析了中央件疲劳试验载荷调试技术,并基于工装上不同测量剖面之间挥舞弯矩相位差异问题提出了一种适用于无人直升机中央件疲劳试验的载荷调试方法。该法主要是通过调试施加在桨叶假件上的挥舞力和摆振力载荷,对中央件四支臂进行相位协调加载,并将桨叶假件和旋翼模拟轴上各测量剖面载荷结合最小二乘法插值计算中央件桨毂中心弯矩和支臂对接面弯矩,使其满足试验和设计要求,从而实现对无人直升机中央件关键剖面位置载荷的联合调试。最后,将新的调试方法应用到首件无人直升机疲劳试验,有效解决了应变测量剖面相位差异较大而引起的目标载荷测量精度低的难题,保障了中央件在地面疲劳试验中准确受载,为其寿命评估提供依据。

Firstly,considering the special framework and the loading character of main rotor hub,and analyzing the phase difference about survey section at two positions on simulated flexible beam,a new fatigue test loading and debugging method of main rotor hub for unmanned helicopter was introduced.This new method could debug the load of hub center and sleeve alignment surface at the same time,by combining linear numerical interpolation formula with measuring loads of simulated flexible beam,from which a satisfactory result could be obtained for the debugging.Finally,applying this new method to the first test of unmanned helicopter,which could not only solve the problem of lower loading accurately,guaranteed the main rotor hub reasonable loaded in the test,but also provided great valuable reference for its fatigue life estimation.