约束阻尼板结构振动声辐射优化

根据经典薄板理论,建立约束阻尼板有限元模型,将其视作镶嵌于无限大刚性障板,利用Rayleigh积分法推导结构的辐射声功率及灵敏度表达式。以一阶峰值频率或频带激励下的声功率最小化为目标,约束阻尼材料体积分数为约束条件,建立拓扑优化模型,采用渐进优化算法,编制了优化计算程序,获得了约束阻尼材料的最优拓扑构型,并与全覆盖板及基板的辐射声功率进行了对比。研究表明:以声功率最小化为目标,对约束阻尼材料布局进行拓扑优化,能有效抑制结构的振动声辐射,为结构低噪声设计提供了重要的理论参考和技术手段。

Topology optimization for the acoustic radiation of constraint damping plate

In basis of the classical plate theory, a laminated damping plate model is built. Regarding the plate inlaid in an infinite rigid baffle, the acoustical power and its sensitivity of the structure are obtained using the Rayleigh integral. The topology optimization model for placement of constraint damping material is established with objective function defined as the minimum of acoustical power under the exciting force of the first mode frequency or frequency band, and the design constraint defined as the volume fraction of damping material. According to the evolutionary structural optimization (ESO) method, the topology optimization of damping plate is conducted and the optimal placement of damping material under the volume requirement is found. Compared with the acoustic radiation of plates without constraint damping material and with full constraint damping material, it is concluded that the optimization method adopted in this paper has an effective control on the acoustic radiation of structure in condition of less damping material usage, and provides a crucial theory reference and technical means for the low noise design of structure.