干摩擦阻尼器对宽频多阶次激励减振效果分析

在对干摩擦阻尼非线性系统响应求解的高阶谐波平衡法、摩擦力时域求解的时间推进法以及时频转换（AFT）法中的关键技术进行介绍的基础上，采用将时频转换法与高阶谐波平衡法相结合的方法对典型航空发动机叶片缘板阻尼器宽频多阶次激励的减振效果进行计算与分析.通过与直接积分法获得的结果进行对比，表明该方法具有较高的计算精度，且计算效率远远高于直接积分法.对比了保留不同谐波阶次时的计算结果，说明对航空发动机中宽频多阶次激励下的干摩擦阻尼系统进行分析计算时需要保留非线性力的高阶谐波成分，才能获得准确的结算结果.干摩擦阻尼器对于不同频率成分激起的共振峰值的最优正压力值不同，实际中应针对激振频率带宽及具体的减振需求，对阻尼器的设计参数进行优化设计，使得系统在整个工作频带上振动响应最小. 

Analysis on damping effect of dry friction damper under wideband multi-harmonic excitation

The key points of multi-harmonic balance method, time-marching procedure of obtainning the friction force in time domain and alternating frequency-time (AFT) domain procedure were introduced. The analysis on damping effect of under-platform damper in aero-engine was investigated using a multi-harmonic balance method combined with an AFT domain procedure, showing that this method is precise and its computational efficiency is much higher than the direct integral method. Influence of the number of harmonics on forced response indicates that more harmonic components should be kept when investigating the damping effect of under-platform damper in aero-engine under wideband multi-harmonic excitation. The optimal normal contact loads of the resonant peaks induced by various excitation frequencies are different; in practice, the design parameters of the friction damper should be optimized in line with the frequency components of excitation and the requirement of vibration attenuation to obtain the minimum response in the whole frequency range.