舰船瞬态噪声激励源传递路径识别方法研究

Study on the Method of Transfer Path Recognition of Ship Transient Noise Excitation Sources

为了有效地控制舰船瞬态噪声,主要从两个方面考虑:激励源和声传播,降低激励源能量,隔绝或减小振动、噪声和激励力的传递途径,而激励源传递路径识别的目的就是评判激励源振动能量传递的主次,进而为减隔振方案的实施提供依据。由于舰船瞬态噪声产生的方式和途径多种多样,加之机械噪声的干扰,致使瞬态噪声激励源及传递路径的判别难度较大,为此,通过开展线谱提取技术、主分量分解和短时相关函数等算法的研究,结合振动-声传递路径的物理模型,从信息相似程度的角度,形成舰船瞬态噪声激励源传递路径识别方法,通过仿真研究给出方法的理论可行性,并以实船为试验平台,开展复杂结构的瞬态激励源传递路径识别试验研究,利用建立的瞬态噪声激励源识别方法,构建激励源振动至辐射声的物理模型,采用从外往内逐层分解的分析方式,准确获取了瞬态激励源振动至辐射声的主要传递路径,验证了该方法的工程有效性和实用性。

In order to effectively control the ship transient noise,two measures can be considered:reducing the energy of the excitation source and isolating the transmission path of vibration and noise.The task of transfer path recognition of the excitation source is to judge the primary and secondary energy transfer paths so as to provide a basis for the implementation of vibration reduction scheme.However,it is difficult to identify the transmission path of ship transient noise excitation source because of the complex transfer path,various noise generation mechanisms and the interference of mechanical noise.For this reason,the methods of line spectrum extraction technology,independent component decomposition and short-time correlation are studied in this paper.Based on the physical model of vibration and sound transmission path,a method for identifying the excitation source of ship’s transient noise is proposed in terms of the information similarity.The feasibility of the method is verified by theoretical simulation.In order to verify the practicability of the method,a testing ship is used as the platform to carry out the experimental research on the transfer path identification of transient excitation source under complex structural conditions.Using the information processing method,the physical model of transmission path from the excitation source vibration to the radiation noise is constructed and the transient excitation source transfer path is obtained accurately by decomposing the outer layer and inside layer.The engineering validity and practicability of the method are verified.