double-frequency vibration

The bending vibration characteristic of a nonlinear cracked rotor is then analyzed. The time frequency characteristics of a cracked rotor after entering double cycle bifurcation are introduced.

然后研究了非线性裂纹转子的弯曲振动特性，给出了进入倍周期分叉后裂纹转子的时域特性和频域特性。

The phenomenon of beats can be observed directly on the double-channel oscillograph and the frequency of alternating current can be measured by the vibration curve of the beats.

在双通道示波器上可直观地观测拍现象，并利用拍振动曲线测量交流电的频率。

The synthesis of under-damping vibrations with the same frequency at two mutual vertical directions is studied and investigated using Model JGYW-2 double-single vibration apparatus.

利用JGYW 2型双单摆振动示波装置对两个相互垂直方向的同频率欠阻尼振动的合成进行了实验研究和理论分析，得到了欠阻尼振动合成的部分图形和表达式。