Forced Response of SDOF
When there is a driving force acting on SDOF system, the system's vibrating
frequency is determined by the driving force frequency and damping ratio.
We are mostly interested in the magnitude and phase shift of the response.
These characteristics are indicated in the system's Frequency Response
Function. When driving frequency is close to the system's natural frequency,
forced vibration magnitude is large. When driving frequency is equal to
natural frequency, forced vibration reaches its maximum magnitude, this
is called resonance. Under resonance, the response's phase shift is 90
degree. The damping ratio also has an effect on FRF. The greater the damping
ratio, the less the forced vibration magnitude.
DANIEL J. INMAN, Engineering Vibration, Prentice Hall, Englewood Cliffs,