粘弹减摆器几何耦合模型及对直升机悬停空中共振的影响.

针对具有几何耦合的非线性粘弹减摆器，在旋转坐标系下建立了其在平衡位置附近的小扰动微分方程，然后通过多桨叶坐标转换的方法将方程变换到不转坐标系中，并与直升机悬停时的线化小扰动方程结合起来进行特征值分析；减摆器静态位移和几何耦合对直升机空中共振稳定性的影响进行了分析。结果表明，粘弹减摆器会提高直升机空中共振稳定性；增大减摆器的静态位移会降低其有效阻尼；对于所考虑的旋翼系统来说，几何耦合可能会减小减摆器的静态位移，从而提高摆振后通型模态的阻尼。

Analytical Model of Elastomeric Lag Damper Kinematic Coupling and Its Effect on Helicopter Air Resonance in Hover

For an elastomeric lag damper with nonlinear properties and kinematic couplings, its differential equation about equilibrium position was derived in a rotating frame. The equation was then transformed into a non\|rotating frame by multi\|blade transformation and incorporated into the rotor/airframe differential equations for eigen analysis. The effects of damper steady displacement and kinematic couplings on helicopter air resonance in hover were analyzed. The results demonstrate that the elastomeric damper can increase helicopter dynamic stability; however, its available damping will decrease as its steady displacement increased. For the notional rotor system, the damper steady displacement will decrease when kinematic couplings are introduced, and hence the regressive lag modal damping can be increased.