A X1

Equation 3.22 is plotted in Figure 3.7, Am versus o/p, for various values of p. It is seen that the peak amplitude, defined as the amplitude at d(Am)/d(o/p) = 0, is greater than the resonant amplitude, defined as the amplitude at o/p = 1. Because they occur practically at the same frequency and it is easy to find the resonant frequency, engineers usually overlook peak amplitude.

3.2.3.4 Damped Forced Vibration with Harmonic Force or Foundation Movement (Transmissibility)

When a harmonic force F cos ot is acting on the mass, the ratio between the amplitude of the force (Af) transmitted to the foundation and the amplitude of the driving force F is called transmissibility and is expressed as follows:

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