Sound insulation performance of an infinite single stiffened laminated plate

Based on the classical laminated plate theory and taking the influence of bending and torsional movement of stiffeners into account, the theoretical sound transmission model of an infinite single stiffened laminated plate excited by a plane sound wave was developed. The transmission loss (TL) expression was derived by using the space harmonic expansion and the principle of virtual work. Then, the accuracy and effectiveness of the proposed model was qualified by comparing model predictions with calculation results in the literature. Finally, the impact of different parameters on the sound insulation performance was studied through numerical calculation. The results indicate that the increase of laying angle has no benefits for the sound insulation performance. Material loss factor only affects the sound insulation at structural resonance frequency. Within the low frequency range, the sound insulation performance decreases significantly as the stiffener spacing is increased. But, in the whole frequency range, the sound insulation performance is improved. The angle of incident wave plays an important role in sound insulation. The oblique incident sound wave transmits through the structure more easily than the normal incident sound.