面向多目标拓扑优化的薄壁件辐射噪声优化设计

Optimal Design of Radiation Noise for Thin-walled Components Based on Multi-objective Topology Optimization

为了研究薄壁件辐射噪声对内燃机噪声的影响,以冲压油底壳为研究对象,将拓扑优化、有限元分析、频响分析、辐射噪声仿真以及消声室振动测试结果集成一体,取油底壳安装位置振动载荷作为输入,进行流固耦合模态参与因子、振动响应计算,获得声辐射频谱;以改善油底壳辐射噪声声压级为最终目标,选取贡献量大的多阶模态固有频率和共振频率下多振动响应峰值为目标关联序列,归一化处理确定加权因子,多目标形貌优化使全频段整体优化效果提升;通过对油底壳结构优化方案进行验证,证明该方法切实可行。结果表明:面向多目标拓扑优化的方法避免了传统设计的单纯依赖设计经验或模仿竞品柴油机结构的盲目性,可用于指导柴油机噪声、振动与声振粗糙度的正向设计。

For the influence of the radiation noise of thin-walled parts on the internal combustion engine noise, the stamping oil pan is used as the research subject in this paper. The topology optimization, finite element analysis, frequency response analysis, radiation noise simulation and anechoic chamber vibration test results are integrated. By taking the vibration load of the installation position of the oil pan as input, the fluid-solid coupling modal participation factor and the vibration response are calculated to obtain the acoustic radiation spectrum. In order to improve the sound pressure level of the radiant noise of the oil pan as the final target, the multi-order modal natural frequency with large contribution and the peak of multi-vibration response under the resonant frequency are the target correlation sequence, the normalized processing determines the weighting factor, and the multi-objective morphology optimization improves the whole-band optimization effect. The method is proved to be feasible by verifying the structure optimization scheme of oil pan. The method of multi- objective topology optimization avoids the simple and dependent design experience of traditional design or the blindness of imitating the structure of competitive diesel engine, which can be used to guide the forward design of diesel engine noise, vibration and acoustic vibration roughness.