基于声功率最小化的结构修正及其优化

Modal Tailoring and Optimization based on the Minimum of the Radiated Sound Power

研究了一种运用结构修改使振动结构表面辐射的声功率达到最小的优化设计方法,这种方法将结构动力学、声学和优化等学科综合为一体。结构在谐频外力作用下产生的声功率可用集中参数和波叠加的方法计算,附加质量块用阻抗表示为外力,通过遗传算法找出对声功率最小有贡献的最优质量点的位置,使结构变为一个“弱辐射体”。

A design tool is presented for minimizing radiated ,sound power from a vibrating structure by modal tailoring. The method links the disciplines of structural dynamics, acoustics and optimization into a unified methodology. The design variables are the positions of the addition of masses to the structure as well as distributions of stiffeners. The ,sound power generated by the structure under a harmonic force is computed with a lumped parameter/wave superposition method. A genetic algorithm is used to find optimal point mass distributions for minimum sound power. It is shown that optimal designs are achieved through converting certain mode shapes of the structure into ＂weak radiators＂,