Читать книгу Engineering Acoustics - Malcolm J. Crocker - Страница 134

The longitudinal wave speed in aluminum is c_L = 5100 m/s. Now, replacing κ = h/(12)^1/2 in Eq. (3.85) yields

Figure 3.29 Measured radiation ratios of unstiffened and stiffened plates for (a) point mechanical excitation and (b) diffuse sound field excitation.

(Source: Reproduced from Ref. [31] with permission. See [30].)

Sound transmission through structures is discussed in Chapter 12 of this book and chapters 66, 76, and 77 of the Handbook of Acoustics [1].

Figure 3.29a and b show the logarithmic value of the radiation efficiency 10log σ plotted against frequency for stiffened and unstiffened plates. See Ref. [27] for further discussion on the radiation efficiency σ_rad, which is also known as radiation ratio.