声场-结构耦合系统灵敏度分析及优化设计研究

SENSITIVITY ANALYSIS AND DESIGN OPTIMIZATION METHOD FOR ACOUSTIC-STRUCTURAL COUPLED SYSTEMS

给出了低频声-结构耦合系统的有限元方程,并在此基础上提出声-结构耦合系统的包含尺寸和形状设计变量的优化设计模型,建立基于灵敏度分析求解的优化设计方法,重点推导了耦合系统的特征频率和声压级响应关于设计变量的灵敏度方程。在JIFEX软件中实现上述理论和算法,并通过灵敏度比较和优化设计的数值算例,进一步说明该研究方法对声结构耦合系统的工程设计具有实用意义。

The numerical methods of finite element analysis for low-frequency acoustic-structural coupled problems are presented.Based on finite element equations,their optimization model and method,including size and shape design variables,are developed.The sensitivity equations of natural frequencies and sound-pressure level response of acoustic-structural systems with respect to design variables are derived out.In order to obtain sensitivities of natural frequencies and sound pressures level,an efficient semi-analytical method is used to determine derivatives of frequencies and sound pressure level with respect to size and shape variables.The sensitivity analysis and the design optimization method mentioned above are implemented with JIFEX,a large-scale finite element analysis and structural optimization software.A full three-dimensional rectangular cavity and a 3D car are modeled with the proposed method to show its significance for engineering design of accoustic-structural coupled systems.