基于一阶剪切变形理论,建立了分析均匀流中周期加筋层合板声振特性的理论模型.该模型应用对流波动方程及边界条件精确考虑了均匀流与层合板的耦合作用,加强筋通过法向线力及扭矩与层合板相互作用,利用傅里叶波数变换和稳相法,得到了位移谱和辐射声压的解析表达式.计算结果与已有公开数据符合良好,验证了模型的有效性.数值结果表明,在高频段不能忽略剪切变形和加强筋扭转运动的影响;增大均匀流速度可降低结构的辐射声压;适当调整板厚和加强筋间距可有效避开结构的辐射声压波峰.
A theoretical model is developed to investigate vibro-acoustic characteristics of shear deformable periodic stiffened laminated composite panels in mean flow, based on the first-order shear deformation theory (FSDT). The convected wave equation and boundary condition are used to account for the exact coupling effect between mean flow and laminated panel. Stiffeners interact with the laminated panel through both the normal line forces and torsional moments. Analytic formulations for the transverse displacement spectra and sound pressure level (SPL) are yielded by employing the Fourier wavenumber transform and the stationary phase method. The model is validated by comparing with existing public data. Excellent agreement is obtained. Numerical results show that the effects of shear deformation and torsional motion of the stiffeners cannot be ignored in high frequency range. SPL can be reduced by increasing the speed of mean flow; it is possible to avoid SPL peaks by altering the thickness and stiffener spacing.