双层圆柱壳体水下振动噪声结构传递路径分析

Structural transfer path analysis for vibration and noise of a submerged cylindrical double-shell

为了实现水下双层圆柱壳体噪声源及传递路径的识别、量化,建立了水下结构振-声传递路径分析(TPA)模型,借助互谱技术、平均技术及加窗进行频响函数估计,并结合正则化方法改善频响函数矩阵求逆的病态问题。进行了双层圆柱壳体水下振动-声辐射试验,实现噪声与结构振动数据的同时基采集。编制TPA程序计算得到合成噪声响应与实测结果吻合很好,利用频谱贡献云图及数据对比的方式分析了传递路径对壳外目标点噪声的贡献,结果与分布运转法所得一致,进而从传递路径的角度找出了对壳外噪声起主导作用的环节。可见,建立的水下双层圆柱壳体结构振-声TPA方法可以有效地识别、量化主要噪声源和噪声的传递路径,并且能够指导水下噪声实时预报和采取针对性的减振降噪措施。

To identify and quantify noise source and transmission path of a submerged cylindrical double-shell,a transfer path analysis（TPA） model of a submerged structure was established,taking window functions and techniques of cross-spectrum and average were used to estimate frequency response function,the regularization method was used to improve the ill-posed problem of frequency response function in seeking exciting force.The vibration and acoustic radiation tests of a submerged cylindrical double-shell were implemented,the data of noise and structural vibration were collected simultaneously.The results of synthetic noise response calculated with TPA program were consistent with the tests ones.The sound contribution of each transfer path to external noise of the cylindrical double-shell was analyzed by using the spectral contribution nephogram and data comparison,the results agreed well with those using the distribution operation method.The multiple transfer paths playing a leading role in external noise were finally determined.The results indicated that the vibration-acoustic TPA method of a submerged cylindrical double-shell can identify and quantify noise source and transmission path,it is of great significance for guiding a real-time prediction of noise radiation and adopting appropriate measures to reduce structural vibration and radiated noise.