多孔材料夹层结构声辐射特性的两尺度拓扑优化设计

Two-scale topology optimization design of sandwich structures of a porous core with respect to sound radiation

基于均匀化计算理论结合结构构型设计和材料构型设计,建立以声辐射功率为目标的两尺度材料/结构协同优化模型,针对夹层结构声学设计问题,开展了声辐射特性拓扑优化研究。分别给出了声辐射功率对宏观和微观设计变量的灵敏度,结合移动渐近线法(MMA)实现了材料/结构两尺度设计。结果表明,声辐射功率两尺度优化改变了夹层结构各阶主振型的形状和顺序,同时也改变了被激发的振型。此外,算例研究了激励频率和约束对优化结果的影响以及声辐射功率目标优化的特殊现象。

A concurrent optimization model with respect to sound power is proposed to find optimal configurations of structure and material based on the homogenization method.A two-scale topology optimization study for minimum sound radiation power is presented to deal with the problem of structural-acoustic optimization of sandwich structures.The sensitivities of radiated acoustic power with respect to design variables for macrostructure and material microstructure are obtained and an optimization of sandwich structures of a porous core is realized by method of moving asympopte（MMA）optimization scheme.Numerical results validate the optimization model and demonstrate that optimization not only change principal mode shapes and natural frequencies＇ sequence of initial structure but also change the excited mode of vibrations.In addition,the influences of excitation frequency and volume fraction on the optimal configurations are investigated and a particular phenomenon is discussed.