铝合金型材与空腔声场耦合振动声学优化设计

Acoustic Optimization of Aluminum Alloy Extrusion Coupled Vibration with Acoustic Cavity

建立了铝合金型材与声场耦合振动的有限元模性,计算了耦合系统的声压响应;以声场和铝合金型材的结构尺寸参数为设计变量,以铝合金型材重量为约束,以声场内响应声压最小为目标,建立了优化数学模型,用零次优化算法对其进行了优化设计研究.优化设计使声场内最大声压降低了1200Pa,而且结构重量也得到了降低.结果表明,优化设计可有效降低声场内的声压,而且零次优化设计方法不用求解声压对设计变量的灵敏度,减小了计算量.

The finite element model of vibration for the aluminum alloy extrusion coupled with acoustic cavity is built to calculate the frequency responses, and the optimization model of reducing the response acoustic pressure is formulated. The structure parameters of the extrusion are used as design variables, the aluminum alloy extrusions weight is used as constrain function, and the zero-order optimization method is applied to optimize the design variables. A acoustic pressure reduction of 1 200 Pa is achieved within 700 - 1 000 Hz with a structure weight reduction of 0.8 kg. The results show that the optimization design has a remarkable efficiency on the noise reduction, and the sensitivity calculation is not necessary in using the zero-order optimization method for the reduction of calculation time.