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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.
Based on the first-order shear deformation theory, a theoretical model for the analysis of the vibra- tional characteristics of a periodically stiffened laminate in a uniform flow is established. The coupled flow of the uniform flow and the laminate is precisely taken into account by the convection-wave equation and the boundary conditions, The normal linear force and torque interact with the laminated plate, and the analytical expressions of displacement spectrum and radiation sound pressure are obtained by Fourier transform and steady-phase method.The calculated results are in good agreement with the published data, The numerical results show that the influence of shear deformation and tendon torsional motion can not be neglected in the high frequency range. Increasing the uniform flow velocity can reduce the radiation sound pressure of the structure. Appropriate adjustment of the thickness of the plate and the spacing of the stiffeners can effectively avoid structural Radiated sound pressure peaks.