Sound radiation and transmission behavior of auxetic core quadrilateral sandwich panels under supersonic flow

Vibroacoustic performance of a quadrilateral sandwich plate under the synergetic effect of aerodynamic pressure and harmonic excitation is analyzed numerically. Layered approach is adopted to model the sandwich plate by considering the equivalent properties of the core and facings. Governing equations, developed utilizing Hamilton’s principle are solved based on differential quadrature approach to analyze the flutter frequency and forced vibration response. Subsequently, Rayleigh integral is used to estimate the acoustic response characteristics. Effect of geometric properties of the core (cell size, wall thickness, and inclined angle) and plate (leading, and trailing-edge angles) is examined. Critical aerodynamic pressure (CAP) is calculated first for the given case and the changes in response characteristics are investigated by varying the CAP. Results indicate that geometric parameters of the core does not influence the CAP, while the core thickness and the leading and trailing edge angles have significant effects. The sound power level (SWL) and transmission loss are observed to be maximum at CAP except in some cases of leading and trailing edge angles.本文对气动压力与简谐激励协同作用下的四边形夹层板的振动声学（Vibroacoustic）性能开展数值分析。采用分层建模法，通过考虑夹芯层与面板的等效特性构建夹层板的力学模型。基于哈密顿原理推导得到的控制方程，借助微分求积法进行求解，以分析其颤振频率与受迫振动响应特性。随后采用瑞利积分估算其声学响应特征。本文考察了夹芯层（胞元尺寸、壁厚与倾角）以及该四边形夹层板（前缘角与后缘角）的几何参数对系统的影响。首先针对给定工况计算临界气动压力（Critical Aerodynamic Pressure, CAP），并通过改变CAP值探究响应特性的变化规律。研究结果表明，夹芯层的几何参数对CAP无显著影响，而夹芯厚度以及前缘与后缘角则对系统性能存在显著作用。观测发现，除部分前缘与后缘角工况外，声功率级（Sound Power Level, SWL）与传声损失在CAP处取得最大值。