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

Figure 4

(a) The effect of the (1,1) mode vibration (𝜔_𝑜= 387.25 × 2π Hz, 𝑡=0.8 mm, 𝑎=𝑏=0.1 m, 𝐷=250 mm, 𝜉=0.01, 𝜎=0.5%, 𝑑=0.4 mm, and 𝜅=10). (b) The effect of the (1,1) mode vibration (𝜔_𝑜= 172.11 × 2π Hz, 𝑡=0.8 mm, 𝑎=𝑏=0.15 m, 𝐷=250 mm, 𝜉=0.01, 𝜎=0.5%, 𝑑=0.4 mm, and 𝜅=10). (c) The effect of the (1,1) mode vibration (𝜔_𝑜= 96.81 × 2π Hz, 𝑡=0.8 mm, 𝑎=𝑏=0.2 m, 𝐷=250 mm, 𝜉= 0.01, 𝜎=0.5%, 𝑑=0.4 mm, and 𝜅=10).

(a)

(b)

(c)