Analytic Formulation for the Sound Absorption of a Panel Absorber under the Effects of Microperforation, Air Pumping, Linear Vibration and Nonlinear Vibration

Figure 5

(a) The effect of excitation level (low to high frequency excitation, 𝜔_𝑜= 387.25 × 2π Hz, 𝑡=0.8 mm, 𝑎=𝑏=0.1 m, 𝐷=250 mm, 𝜉=0.01, 𝜎=0.5%, and 𝑑=0.4 mm). (b) The effect of excitation level (high to low frequency excitation, 𝜔_𝑜=387.25×2𝜋𝐻𝑧, 𝑡=0.8 mm, 𝑎=𝑏=0.1 m, 𝐷=250 mm, 𝜉=0.01, 𝜎=0.5%, and 𝑑=0.4 mm).

(a)

(b)