复合材料传动轴的弯曲振动分析

为改善直升机传动轴的动力学特性,研究了非惯性系下复合材料传动轴的弯曲振动问题.根据质心运动定理导出了非惯性系下两端支承的倾斜纤维增强复合材料传动轴的弯曲振动方程,用Galerkin法求得方程的解.在此基础上,分析了质量偏心、阻尼、惯性力和重力对振幅的影响.研究表明：复合材料传动轴比钢、铝合金传动轴同阶弯曲固有频率大,相邻阶之间不产生共振的频率范围大、静挠度小、振幅小.惯性力不变时,传动轴的最大横向位移等于惯性力和重力产生的静挠度与质量偏心产生的动挠度幅值之和;惯性力变化时,传动轴产生动挠度.

Bending Vibration Analysis of Composite Transmission Shaft

To improve the dynamic characteristics of a helicopter transmission shaft, bending vibration of a composite transmission shaft was investigated under a non-inertial system. Based on theorem of the motion for center of mass, a bending vibration equation for a tilting fiber composite transmission shaft with two supports was derived under a non-inertial system, and its solution was obtained by the Galerkin method. The effects of eccentric mass, damping, inertia force and gravity on the vibration amplitude were analyzed. The results show that a fiber composite transmission shaft has a larger bending natural frequency than a steel or aluminum alloy transmission shaft and a larger frequency range of non-resonance between adjacent orders, smaller static deflection and amplitude. When inertia force of a transmission shaft does not change, its maximum transversal displacement is equal to the sum of the static deflection produced by inertia force and gravity and the amplitude of deflection induced by eccentric mass, and when inertia force of a transmission shaft changes, dynamic deflection is produced.