The former causes forced vibration at the circular frequency of the crank shaft and the latter causes transient vibration at the natural frequency of the press. 惯性力激发的振动是以曲轴转速为频率的强迫振动，加工力激发的是以压机固有频率为频率的过渡振动。
In the regenerative liquid propellant gun,the coupling oscillation of the fluid sys-tem in the reservoir including free vibration and forced vibration may be formed. 在再生式液体发射药火炮中，贮液室流体系统可能发生由自激振动与强迫振动构成的耦合振荡，在喷射结束期很可能形成共振。
