韩梦威
合肥工业大学
基于特征频率拓扑优化的声腔表面吸声材料布局设计
基于特征频率拓扑优化的声腔表面吸声材料布局设计
韩梦威1,郑昌军1,毕传兴1
(1.合肥工业大学噪声振动工程研究所,安徽合肥230009)
摘要:在声腔表面铺设多孔吸声材料是抑制声腔共鸣噪声的一种有效手段,然而全覆盖的铺设方式并不总能达到最优的降噪效果。为了在提升降噪性能的同时减少材料用量,本文提出了一种拓扑优化设计方法,用于确定多孔吸声材料在声腔表面的最优布局。该方法直接以声腔系统特征频率为优化目标,特征频率实部代表声腔共振频率,而虚部代表阻尼损失,可用来表征吸声材料抑制声腔共振噪声的性能。因此,本文构建了以某一阶或多阶特征频率虚部为优化目标的拓扑优化模型,该方法基于固体各向同性材料惩罚模型建立多孔吸声材料阻尼参数的插值模型,引入吸声材料属性和单元材料密度之间的关系,以单元材料密度为设计变量,边界上每个单元均对应一个设计变量。对于由多孔吸声材料频变特性导致的非线性特征值求解问题,本文采用围道积分法对声腔非线性特征值问题进行线性化处理;在此基础上,推导出非线性特征频率灵敏度的计算式,并借助移动渐近线法对设计变量进行迭代求解,从而实现吸声材料布局的拓扑优化设计。
Design of Sound-Absorbing Materials Layout on Acoustic Cavity Surfaces Based on Eigenfrequency Topology Optimization
Abstract: Covering the surfaces of acoustic cavities with porous sound-absorbing materials is an effective approach to suppress the resonant noise of cavities. However, a fully-covered layout does not always achieve optimal noise reduction performance. To enhance the noise reduction performance with minimal material usage, this paper proposes a topology optimization design method to determine the optimal layout of porous sound-absorbing materials on the surface of the acoustic cavity. The optimization directly targets the eigenfrequencies of the cavity system, where the real part represents the resonance frequency and the imaginary part reflects damping loss, serving as a measure of the material’s capability to suppress resonance. A topology optimization model is constructed by taking the imaginary part of one or multiple eigenfrequencies as the objective function. An interpolation scheme for the damping parameters is developed based on the Solid Isotropic Material with Penalization (SIMP) approach, introducing the relationship between the porous material properties and the element densities, with each boundary element assigned a design variable. To address the nonlinear eigenvalue problem arising from the frequency-dependent characteristics of porous materials, the contour integral method is employed for linearization. On this basis, the sensitivity formulation of nonlinear eigenfrequencies is derived, and the Method of Moving Asymptotes (MMA) is adopted to iteratively update the design variables. This framework enables the topology optimization of sound-absorbing material layouts, achieving effective suppression of cavity resonances with reduced material usage.
Keywords: acoustic cavity resonance; porous sound-absorbing materials; topology optimization; nonlinear eigenfrequencies; contour integral
合肥工业大学机械工程学院在读博士生,导师:郑昌军教授