减小临界振幅的机理与试验研究

对于受迫振动系统，当激励频率增加并且通过共振(临界)频率时，系统的振幅将达到其峰值．通过相位调制可以有效地减小共振振幅，其机理是振幅的变化取决于相应和激励之间的相位差，而此相位差可以通过控制激励频率的变化规律进行调制．该方法由受变频率脉冲激励的悬臂梁进行了实验验证．实验结果表明，对于给定的最大频率增加速率，通过相位调制可以将共振振幅减小18％左右．

Experiment verification for reducing the vibration amplitude at resonance

A forced vibration system will approach its maximum vibration amplitude at resonance, if the resonant frequency has to be passed. This peak amplitude can be reduced by means of phase modulation technique, whose mechanism is that the increase/decrease of vibration amplitude is closely related to the phase difference between the response and excitement, and the phase difference can be modulated by controlling the course of excitement frequency. Experimental verification was conducted with a cantilever beam subjected to pulses excitement. For the given maximum rate of increasing the excitement frequency, the maximum vibration amplitude of the cantilever was reduced about 18 % with phase modulating during the passage of the first resonant frequency.