多源激励水下复杂壳体结构振动与辐射声场试验研究

Experimental Research on Vibration and Acoustic Radiation of the Submerged Complicated Shell Structure with Multiple Excitations

设计了一个接近实际情况的多舱段复杂壳体模型,安装小型机械设备,分别进行了单台设备激励与多台设备同时激励的水下复杂壳体振动与声辐射试验;试验结果表明,多源激励下水中复杂壳体的结构响应、辐射声场近似为单源激励下结构响应、辐射声场的非相干叠加。然后从结构声辐射理论上推导了激励源与结构响应、辐射声场之间的传递关系,并以两个源激励为例分析了非相干叠加引起的误差,从而解释了多源激励下结构响应、辐射声场近似为单源激励下结构响应、辐射声场非相干叠加的合理性。这些研究表明,非相干叠加方法可推广应用于水下复杂壳体在多源激励情况下的振动与声场计算,对指导工程设计具有重要价值。

A design of complex multiple compartment shell model with some small mechanical facilities, which is used to simulate real ships, is introduced in this paper. The underwater vibration and acoustic radiation experiments with single and multiple excitations are implemented and related research work is also provided.Results show that the response of complex structure and sound pressure which are caused by multiple excitations can be approximately analysed by the approach of in- coherent superposition of individual excitation.The transitive relation between the vibro-acoustic characteristics of the submerged complex structure with multiple excitations and that with individual excitation are deduced analytically. The error of incoherent superposition is also estimated by an example of with two excitation so as to validate this approximation.It is indicated that the incoherent superposition approach can be applied to investigate the vibration and sound radiation of more complex multiple compartment shell structures with multiple excitations and it is especially useful for both qualitative and quantitative evaluation at design stages of practical structures.