无限大单板和空腔双板隔声量研究

Study on Sound Transmission Losses of Infinite Panels and Hollow Double Panels

考虑声波垂直入射和斜入射两种情况,针对无限大单板和空腔双板两种结构,运用波传递法和结构弯曲波法分别得到这2种结构的隔声量,给出隔声谷值的计算公式并分析其物理意义,包括“板-空腔-板”共振频率、驻波共振频率和板的吻合频率。通过隔声量曲线对比,描述两条曲线变化过程和整体变化趋势,进而对波传递法和结构弯曲波法的优缺点进行分析。对于薄板结构,当声波垂直入射时,波传递法和结构弯曲波法的隔声量曲线相互吻合,通过推导得到两种方法的等效条件;当声波斜入射时,波传递法的计算结果变得不精确,而结构弯曲波法的计算结果依然具有可靠性。

Considering vertical and oblique incidences of acoustic waves, the sound insulations of the infinite panel and the hollow double panel are analyzed by using wave transfer method (WTM) and structural bending wave method (BWM). Their sound insulation curves and valleys are obtained. Calculation formulas and physical meanings of the sound insulation valleys are given, including the "mass-cavity-mass" resonance frequency, standing wave resonance frequency, and panel coincidence frequency. Through the mutual comparison of the two sound insulation curves, the change processes and the overall change trends are depicted. Furthermore, the advantages and disadvantages of the two methods of WTM and BWM are discussed. For the thin plate structure, when the acoustic wave is vertically incident, the sound insulation curves provided by WTM and BWM coincide perfectly each other. And the equivalent conditions of the two methods are derived. When the acoustic wave is obliquely incident, the calculation result by WTM becomes inaccurate, while the calculation result by BWM is still reliable.