Frequency Response

The harmonic excitation is the most widely used continuous excitation in vehicle vibration applications. Any combination of \(\sin \) and \(\cos \) functions is called a harmonic function. Frequency response analysis is simple and straightforward because the response of linear discrete vibrating systems to harmonic excitation is harmonic with proportional magnitude. The magnitudes of harmonic responses are functions of the excitation frequencies and depend on the system parameters. The goal of frequency response analysis is to find and plot the magnitude of the harmonic response versus excitation frequency. Such a function is called the frequency response and indicates the behavior of the system at different excitation frequencies. Figure 7.1 illustrates the only four types of harmonically excited one-DOF systems.