随机激励结构-声场耦合振动声学数值仿真研究

Research on Acoustic Numerical Simulation for Structure-Acoustic Coupled Random Vibration

结构随机振动产生的噪声场为随机声场,其数值仿真对随机振动结构的降噪设计有重要意义。建立了结构-声场耦合随机振动的有限元模型,推导了声学响应函数的计算方法,利用声学响应函数和激励谱密度函数推导了响应声压的自谱密度函数。以薄板和三维声场耦合随机振动为算例,计算了1Hz～200Hz的声学频率响应函数,并计算了系统受常谱密度和变谱密度随机载荷激励时系统的声学响应。理论推导和实例结果表明,随机振动的声学响应特性取决于声学频率响应函数和激励谱密度函数。

The acoustic field of structure random vibration subjected to a random load is a random acoustic field, and its numerical simulation is very important to noise reduction. The finite element model of the structure-acoustic couple vibration was set up, and the acoustic response function was deduced, and the acoustic pressure response feature was formulated by the vibration acoustic field coupled with a plate as an example. The results show that acoustic response feature of random vibration depends on the acoustic response function and the spectral density function of the stimulating load.